diff options
| -rw-r--r-- | articles/ui/hotcrp-review-28A.txt | 71 | ||||
| -rw-r--r-- | articles/ui/sigalternate.cls | 1649 | ||||
| -rw-r--r-- | articles/ui/ui_short.tex | 260 | ||||
| -rw-r--r-- | test/run_tests.js | 3 |
4 files changed, 1983 insertions, 0 deletions
diff --git a/articles/ui/hotcrp-review-28A.txt b/articles/ui/hotcrp-review-28A.txt new file mode 100644 index 000000000..f9512df03 --- /dev/null +++ b/articles/ui/hotcrp-review-28A.txt @@ -0,0 +1,71 @@ +=========================================================================== + SOUPS '16 Review #28A +--------------------------------------------------------------------------- + Paper #28: Taler: Usable, privacy-preserving payments for the Web +--------------------------------------------------------------------------- + + + Overall merit: 1. Reject + Reviewer expertise: 2. Some familiarity + + ===== Paper summary ===== + +This paper presents Taler, an alternative electronic payment architecture leveraging blind signature [7] that provide anonymity and privacy. The paper describes various workflows of how Taler is used by consumers, merchants, exchanges, and auditors. There are several advantages to Taler over current crypto-currencies, such as Bitcoin. + + ===== Comments for author(s) ===== + +Unfortunately, this paper is not ready for publication at SOUPS, for the following reasons: + +1. While the paper makes significant claims about Taler's usability, there is no usability testing done whatsoever. Thus, all claims of Taler's usability are completely unsubstantiated. Until there is some usability testing performed for evaluating Taler's usability, SOUPS is not an appropriate venue for publication of this work. + +2. There are several points made throughout the paper that are insufficiently clear, some of which include: + + * "there have been many incidents where such parties then embezzled [Bitcoin] funds from their customers." Then surely citations can be provided as examples? + + * The text in Figures 1, 2, 3, 5, and 7 is far too small to read and make sense of. + + * "The use of an external payment application makes wallet-based payments significantly less browser-friendly than ordinary card payments..." This is not self-evident, and requires a citation or further explanation. Otherwise, couldn't a browser extension be able to provide Bitcoin transaction functionality? + + * "As a result, the network must expend considerable computational resources to keep this value high. In fact, 'a single Bitcoin transaction uses roughly enough electricity to power 1.57 American households for a day'. [22] These costs are largely hidden by speculation in BTC..." This last phrase requires additional explanation, which may be out of scope for a usable privacy and security paper (rather than an economics paper). Still, something should be fixed here. + + * "Mixnets afford protection against this..." What is a "mixnet"? At the very least, a citation should be provided. + + * "...making Bitcoin highly amenable to tax evasion, money laundering, and sales of contraband. As a result, anonymity tools like mixnets do not enjoy particularly widespread support in the Bitcoin community where many participants seek to make the currency appear more legitimate." This doesn't quite seem to make sense; wouldn't anonymity advocates who support Bitcoin also support anonymity tools (such as mixnets)? + + * "Naturally, this is exactly the kind of interaction we would like to avoid for usability." So how do you propose to resolve this usability challenge? Banks are typically slow to adopt new technology, so Taler must be usable without banks' cooperation (and with smaller banks that do not have the resources to support diverse payment systems). + + * The description in Section 3.1 "Withdrawing coins" does not clearly explain how the customer's funds move from the exchange to the customer's wallet. It is also not explicitly clear how anonymity is preserved throughout the coin withdraw process. + + * While it is sufficiently clear who the customers and merchants are, it is not clear in Section 3 who would run the exchanges, and why users should trust the exchanges with their money in transit from their bank account to their wallet. It is also not clear who the auditors would be. + + * "Merchants can also set a ceiling for the maximum amount of transaction fees they are willing to cover. Usually these details should not matter for the customer, as we expect most merchants to allow most accredited exchange providers, and for exchanges to operate with transaction fees acceptable to most merchants." This expectation seems insufficiently substantiated, thus requiring additional explanation. Why do you expect this of merchants and exchanges? How will this be enforced? + + * Since much of the customer-merchant transaction occurs on the client machine, it should be made more explicitly clear why a customer cannot (i.e., what prevents a customer from) simply add(ing) coins to their own wallet to generate currency from thin air. + + * "In Taler, customers incur the risk of wallet loss or theft. We believe customers can manage this risk effectively because they manage similar risks of losing cash in a physical wallet. Unlike physical wallets, Taler's wallet could be backed up to secure against loss of a device." This confidence in users' ability to secure their computers seems unfounded, given past research that shows users are often tricked into installing malware: + ** N. Christin et al. It's all about the Benjamins: An empirical study on incentivizing users to ignore security advice. Financial Cryptography and Data Security. Springer, 2011. + ** H. Asghari et al. Post-mortem of a zombie: conficker cleanup after six years. USENIX Security Symposium. USENIX, 2015. + ** K. Aytes, and T. Connolly. Computer security and risky computing practices: A rational choice perspective. Advanced topics in end user computing 4, 2005. + ** P. Bryant, S. Furnell, and A. Phippen. Improving protection and security awareness amongst home users. Advances in Networks, Computing and Communications 4. April 2008. + + +Some other comments the authors may which to take into consideration include: + +* "The future Internet needs a secure, usable and privacy preserving micropayment system that is not backed by a 'crypto currency'." This is a very strong and controversial statement to make, especially without having first provided evidence to support it. I'd advise putting this sentence at the end of the paragraph, after the references have been cited. + +* The second paragraph in the Introduction is difficult to follow and seems a lot more controversial than a motivating paragraph needs to be. + +* "These institutions also provide detailed instructions for how to validate the authenticity of the coins or bills..." Are there any citations on how difficult and seldom currency authenticity verification is performed? These may be useful lessons for developing new currencies, whereby currency authenticity needs of be an easy, quick, and straightforward task if users are expected to perform it. + +* Section 2 is an interesting and appropriate framing for the paper, but it is surprising this hasn't been done before. Has no other published work ever compared the different forms of currency? For example, a similar comparison of electronic payment systems was performed by H.C. Yu et al. Electronic payment systems: an analysis and comparison of types. Technology in Society 24(3), 2002, but is not cited by this paper. + +* While Bitcoin is probably the most popular, it is not the only crypto-currency. At least a brief comparison (or at least a reference to a paper discussing them) between Bitcoin and other crypto-currencies in Section 2 is warranted. Even better would be for Section 2.3 to address crypto-currencies in general, and use Bitcoin as an example. + +* Referencing a PhD thesis [14] is a bit uncommon, especially for such a strong and impactful statement as "Given numerous TLS protocol and implementation flaws as well as X.509 key management incidents in recent years [14], the security provided by TLS is at best questionable." Is there no peer-reviewed conference or journal citation that can be used instead? + +* "Taler achieves anonymity for buyers using blind signatures [7]. Ever since their discovery thirty years ago, cryptographers have viewed blind signatures as the optimal cryptographic primitive for consumer level transaction systems." If so, then why do you suppose it's taken 30 years for someone to propose a blind crypto transaction system? + +* "Exchanges perform online detection of double spending," these concepts should be defined somewhere, for readers unfamiliar with them. + +* "For a traditional store, an NFC protocol..." An acronym must be defined before or at the time it is first used. + diff --git a/articles/ui/sigalternate.cls b/articles/ui/sigalternate.cls new file mode 100644 index 000000000..ea3b37088 --- /dev/null +++ b/articles/ui/sigalternate.cls @@ -0,0 +1,1649 @@ +% SIG-ALTERNATE.CLS - VERSION 2.4 +% "COMPATIBLE" WITH THE "ACM_PROC_ARTICLE-SP.CLS" V3.2SP +% Gerald Murray - April 22nd. 2009 +% +% ---- Start of 'updates' ---- +% +% Changed $5 fee to $10 - Gerry +% April 22nd. 2009 - Fixed 'Natbib' incompatibility problem - Gerry +% April 22nd. 2009 - Fixed 'Babel' incompatibility problem - Gerry +% April 22nd. 2009 - Inserted various bug-fixes and improvements - Gerry +% +% To produce Type 1 fonts in the document plus allow for 'normal LaTeX accenting' in the critical areas; +% title, author block, section-heads, confname, etc. etc. +% i.e. the whole purpose of this version update is to NOT resort to 'inelegant accent patches'. +% After much research, three extra .sty packages were added to the the tail (ae, aecompl, aeguill) to solve, +% in particular, the accenting problem(s). We _could_ ask authors (via instructions/sample file) to 'include' these in +% the source .tex file - in the preamble - but if everything is already provided ('behind the scenes' - embedded IN the .cls) +% then this is less work for authors and also makes everything appear 'vanilla'. +% NOTE: all 'patchwork accenting" has been commented out (here) and is no longer 'used' in the sample .tex file (either). +% Gerry June 2007 +% +% Patch for accenting in conference name/location. Gerry May 3rd. 2007 +% Rule widths changed to .5, author count (>6) fixed, roll-back for Type 3 problem. Gerry March 20th. 2007 +% Changes made to 'modernize' the fontnames but esp. for MikTeX users V2.4/2.5 - Nov. 30th. 2006 +% Updated the \email definition to allow for its use inside of 'shared affiliations' - Nov. 30th. 2006 +% Fixed the 'section number depth value' - Nov. 30th. 2006 +% +% Footnotes inside table cells using \minipage (Oct. 2002) +% Georgia fixed bug in sub-sub-section numbering in paragraphs (July 29th. 2002) +% JS/GM fix to vertical spacing before Proofs (July 30th. 2002) +% +% Made the Permission Statement / Conference Info / Copyright Info +% 'user definable' in the source .tex file OR automatic if +% not specified. +% +% Allowance made to switch default fonts between those systems using +% normal/modern font names and those using 'Type 1' or 'Truetype' fonts. +% See LINE NUMBER 255 for details. +% Also provided for enumerated/annotated Corollaries 'surrounded' by +% enumerated Theorems (line 848). +% Gerry November 11th. 1999 +% +% ---- End of 'updates' ---- +% +\def\fileversion{v2.4} % for ACM's tracking purposes +\def\filedate{April 22, 2009} % Gerry Murray's tracking data +\def\docdate {Wednesday 22nd. April 2009} % Gerry Murray (with deltas to doc} +\usepackage{epsfig} +\usepackage{amssymb} +\usepackage{amsmath} +\usepackage{amsfonts} +% Need this for accents in Arial/Helvetica +%\usepackage[T1]{fontenc} % Gerry March 12, 2007 - causes Type 3 problems (body text) +%\usepackage{textcomp} +% +% SIG-ALTERNATE DOCUMENT STYLE +% G.K.M. Tobin August-October 1999 +% adapted from ARTICLE document style by Ken Traub, Olin Shivers +% also using elements of esub2acm.cls +% HEAVILY MODIFIED, SUBSEQUENTLY, BY GERRY MURRAY 2000 +% ARTICLE DOCUMENT STYLE -- Released 16 March 1988 +% for LaTeX version 2.09 +% Copyright (C) 1988 by Leslie Lamport +% +% +%%% sig-alternate.cls is an 'ALTERNATE' document style for producing +%%% two-column camera-ready pages for ACM conferences. +%%% THIS FILE DOES NOT STRICTLY ADHERE TO THE SIGS (BOARD-ENDORSED) +%%% PROCEEDINGS STYLE. It has been designed to produce a 'tighter' +%%% paper in response to concerns over page budgets. +%%% The main features of this style are: +%%% +%%% 1) Two columns. +%%% 2) Side and top margins of 4.5pc, bottom margin of 6pc, column gutter of +%%% 2pc, hence columns are 20pc wide and 55.5pc tall. (6pc =3D 1in, approx) +%%% 3) First page has title information, and an extra 6pc of space at the +%%% bottom of the first column for the ACM copyright notice. +%%% 4) Text is 9pt on 10pt baselines; titles (except main) are 9pt bold. +%%% +%%% +%%% There are a few restrictions you must observe: +%%% +%%% 1) You cannot change the font size; ACM wants you to use 9pt. +%%% 3) You must start your paper with the \maketitle command. Prior to the +%%% \maketitle you must have \title and \author commands. If you have a +%%% \date command it will be ignored; no date appears on the paper, since +%%% the proceedings will have a date on the front cover. +%%% 4) Marginal paragraphs, tables of contents, lists of figures and tables, +%%% and page headings are all forbidden. +%%% 5) The `figure' environment will produce a figure one column wide; if you +%%% want one that is two columns wide, use `figure*'. +%%% +% +%%% Copyright Space: +%%% This style automatically reserves 1" blank space at the bottom of page 1/ +%%% column 1. This space can optionally be filled with some text using the +%%% \toappear{...} command. If used, this command must be BEFORE the \maketitle +%%% command. If this command is defined AND [preprint] is on, then the +%%% space is filled with the {...} text (at the bottom); otherwise, it is +%%% blank. If you use \toappearbox{...} instead of \toappear{...} then a +%%% box will be drawn around the text (if [preprint] is on). +%%% +%%% A typical usage looks like this: +%%% \toappear{To appear in the Ninth AES Conference on Medievil Lithuanian +%%% Embalming Technique, June 1991, Alfaretta, Georgia.} +%%% This will be included in the preprint, and left out of the conference +%%% version. +%%% +%%% WARNING: +%%% Some dvi-ps converters heuristically allow chars to drift from their +%%% true positions a few pixels. This may be noticeable with the 9pt sans-serif +%%% bold font used for section headers. +%%% You may turn this hackery off via the -e option: +%%% dvips -e 0 foo.dvi >foo.ps +%%% +\typeout{Document Class 'sig-alternate' <22nd. April '09>. Modified by G.K.M. Tobin/Gerry Murray} +\typeout{Based in part upon document Style `acmconf' <22 May 89>. Hacked 4/91 by} +\typeout{shivers@cs.cmu.edu, 4/93 by theobald@cs.mcgill.ca} +\typeout{Excerpts were taken from (Journal Style) 'esub2acm.cls'.} +\typeout{****** Bugs/comments/suggestions/technicalities to Gerry Murray -- murray@hq.acm.org ******} +\typeout{Questions on the style, SIGS policies, etc. to Adrienne Griscti griscti@acm.org} +\oddsidemargin 4.5pc +\evensidemargin 4.5pc +\advance\oddsidemargin by -1in % Correct for LaTeX gratuitousness +\advance\evensidemargin by -1in % Correct for LaTeX gratuitousness +\marginparwidth 0pt % Margin pars are not allowed. +\marginparsep 11pt % Horizontal space between outer margin and + % marginal note + + % Top of page: +\topmargin 4.5pc % Nominal distance from top of page to top of + % box containing running head. +\advance\topmargin by -1in % Correct for LaTeX gratuitousness +\headheight 0pt % Height of box containing running head. +\headsep 0pt % Space between running head and text. + % Bottom of page: +\footskip 30pt % Distance from baseline of box containing foot + % to baseline of last line of text. +\@ifundefined{footheight}{\newdimen\footheight}{}% this is for LaTeX2e +\footheight 12pt % Height of box containing running foot. + +%% Must redefine the top margin so there's room for headers and +%% page numbers if you are using the preprint option. Footers +%% are OK as is. Olin. +\advance\topmargin by -37pt % Leave 37pt above text for headers +\headheight 12pt % Height of box containing running head. +\headsep 25pt % Space between running head and text. + +\textheight 666pt % 9 1/4 column height +\textwidth 42pc % Width of text line. + % For two-column mode: +\columnsep 2pc % Space between columns +\columnseprule 0pt % Width of rule between columns. +\hfuzz 1pt % Allow some variation in column width, otherwise it's + % too hard to typeset in narrow columns. + +\footnotesep 5.6pt % Height of strut placed at the beginning of every + % footnote =3D height of normal \footnotesize strut, + % so no extra space between footnotes. + +\skip\footins 8.1pt plus 4pt minus 2pt % Space between last line of text and + % top of first footnote. +\floatsep 11pt plus 2pt minus 2pt % Space between adjacent floats moved + % to top or bottom of text page. +\textfloatsep 18pt plus 2pt minus 4pt % Space between main text and floats + % at top or bottom of page. +\intextsep 11pt plus 2pt minus 2pt % Space between in-text figures and + % text. +\@ifundefined{@maxsep}{\newdimen\@maxsep}{}% this is for LaTeX2e +\@maxsep 18pt % The maximum of \floatsep, + % \textfloatsep and \intextsep (minus + % the stretch and shrink). +\dblfloatsep 11pt plus 2pt minus 2pt % Same as \floatsep for double-column + % figures in two-column mode. +\dbltextfloatsep 18pt plus 2pt minus 4pt% \textfloatsep for double-column + % floats. +\@ifundefined{@dblmaxsep}{\newdimen\@dblmaxsep}{}% this is for LaTeX2e +\@dblmaxsep 18pt % The maximum of \dblfloatsep and + % \dbltexfloatsep. +\@fptop 0pt plus 1fil % Stretch at top of float page/column. (Must be + % 0pt plus ...) +\@fpsep 8pt plus 2fil % Space between floats on float page/column. +\@fpbot 0pt plus 1fil % Stretch at bottom of float page/column. (Must be + % 0pt plus ... ) +\@dblfptop 0pt plus 1fil % Stretch at top of float page. (Must be 0pt plus ...) +\@dblfpsep 8pt plus 2fil % Space between floats on float page. +\@dblfpbot 0pt plus 1fil % Stretch at bottom of float page. (Must be + % 0pt plus ... ) +\marginparpush 5pt % Minimum vertical separation between two marginal + % notes. + +\parskip 0pt plus 1pt % Extra vertical space between paragraphs. +\parindent 9pt % GM July 2000 / was 0pt - width of paragraph indentation. +\partopsep 2pt plus 1pt minus 1pt% Extra vertical space, in addition to + % \parskip and \topsep, added when user + % leaves blank line before environment. + +\@lowpenalty 51 % Produced by \nopagebreak[1] or \nolinebreak[1] +\@medpenalty 151 % Produced by \nopagebreak[2] or \nolinebreak[2] +\@highpenalty 301 % Produced by \nopagebreak[3] or \nolinebreak[3] + +\@beginparpenalty -\@lowpenalty % Before a list or paragraph environment. +\@endparpenalty -\@lowpenalty % After a list or paragraph environment. +\@itempenalty -\@lowpenalty % Between list items. + +%\@namedef{ds@10pt}{\@latexerr{The `10pt' option is not allowed in the `acmconf' +\@namedef{ds@10pt}{\ClassError{The `10pt' option is not allowed in the `acmconf' % January 2008 + document style.}\@eha} +%\@namedef{ds@11pt}{\@latexerr{The `11pt' option is not allowed in the `acmconf' +\@namedef{ds@11pt}{\ClassError{The `11pt' option is not allowed in the `acmconf' % January 2008 + document style.}\@eha} +%\@namedef{ds@12pt}{\@latexerr{The `12pt' option is not allowed in the `acmconf' +\@namedef{ds@12pt}{\ClassError{The `12pt' option is not allowed in the `acmconf' % January 2008 + document style.}\@eha} + +\@options + +\lineskip 2pt % \lineskip is 1pt for all font sizes. +\normallineskip 2pt +\def\baselinestretch{1} + +\abovedisplayskip 9pt plus2pt minus4.5pt% +\belowdisplayskip \abovedisplayskip +\abovedisplayshortskip \z@ plus3pt% +\belowdisplayshortskip 5.4pt plus3pt minus3pt% +\let\@listi\@listI % Setting of \@listi added 9 Jun 87 + +\def\small{\@setsize\small{9pt}\viiipt\@viiipt +\abovedisplayskip 7.6pt plus 3pt minus 4pt% +\belowdisplayskip \abovedisplayskip +\abovedisplayshortskip \z@ plus2pt% +\belowdisplayshortskip 3.6pt plus2pt minus 2pt +\def\@listi{\leftmargin\leftmargini %% Added 22 Dec 87 +\topsep 4pt plus 2pt minus 2pt\parsep 2pt plus 1pt minus 1pt +\itemsep \parsep}} + +\def\footnotesize{\@setsize\footnotesize{9pt}\ixpt\@ixpt +\abovedisplayskip 6.4pt plus 2pt minus 4pt% +\belowdisplayskip \abovedisplayskip +\abovedisplayshortskip \z@ plus 1pt% +\belowdisplayshortskip 2.7pt plus 1pt minus 2pt +\def\@listi{\leftmargin\leftmargini %% Added 22 Dec 87 +\topsep 3pt plus 1pt minus 1pt\parsep 2pt plus 1pt minus 1pt +\itemsep \parsep}} + +\newcount\aucount +\newcount\originalaucount +\newdimen\auwidth +\auwidth=\textwidth +\newdimen\auskip +\newcount\auskipcount +\newdimen\auskip +\global\auskip=1pc +\newdimen\allauboxes +\allauboxes=\auwidth +\newtoks\addauthors +\newcount\addauflag +\global\addauflag=0 %Haven't shown additional authors yet + +\newtoks\subtitletext +\gdef\subtitle#1{\subtitletext={#1}} + +\gdef\additionalauthors#1{\addauthors={#1}} + +\gdef\numberofauthors#1{\global\aucount=#1 +\ifnum\aucount>3\global\originalaucount=\aucount \global\aucount=3\fi %g} % 3 OK - Gerry March 2007 +\global\auskipcount=\aucount\global\advance\auskipcount by 1 +\global\multiply\auskipcount by 2 +\global\multiply\auskip by \auskipcount +\global\advance\auwidth by -\auskip +\global\divide\auwidth by \aucount} + +% \and was modified to count the number of authors. GKMT 12 Aug 1999 +\def\alignauthor{% % \begin{tabular} +\end{tabular}% + \begin{tabular}[t]{p{\auwidth}}\centering}% + +% *** NOTE *** NOTE *** NOTE *** NOTE *** +% If you have 'font problems' then you may need +% to change these, e.g. 'arialb' instead of "arialbd". +% Gerry Murray 11/11/1999 +% *** OR ** comment out block A and activate block B or vice versa. +% ********************************************** +% +% -- Start of block A -- (Type 1 or Truetype fonts) +%\newfont{\secfnt}{timesbd at 12pt} % was timenrb originally - now is timesbd +%\newfont{\secit}{timesbi at 12pt} %13 Jan 00 gkmt +%\newfont{\subsecfnt}{timesi at 11pt} % was timenrri originally - now is timesi +%\newfont{\subsecit}{timesbi at 11pt} % 13 Jan 00 gkmt -- was times changed to timesbi gm 2/4/2000 +% % because "normal" is italic, "italic" is Roman +%\newfont{\ttlfnt}{arialbd at 18pt} % was arialb originally - now is arialbd +%\newfont{\ttlit}{arialbi at 18pt} % 13 Jan 00 gkmt +%\newfont{\subttlfnt}{arial at 14pt} % was arialr originally - now is arial +%\newfont{\subttlit}{ariali at 14pt} % 13 Jan 00 gkmt +%\newfont{\subttlbf}{arialbd at 14pt} % 13 Jan 00 gkmt +%\newfont{\aufnt}{arial at 12pt} % was arialr originally - now is arial +%\newfont{\auit}{ariali at 12pt} % 13 Jan 00 gkmt +%\newfont{\affaddr}{arial at 10pt} % was arialr originally - now is arial +%\newfont{\affaddrit}{ariali at 10pt} %13 Jan 00 gkmt +%\newfont{\eaddfnt}{arial at 12pt} % was arialr originally - now is arial +%\newfont{\ixpt}{times at 9pt} % was timenrr originally - now is times +%\newfont{\confname}{timesi at 8pt} % was timenrri - now is timesi +%\newfont{\crnotice}{times at 8pt} % was timenrr originally - now is times +%\newfont{\ninept}{times at 9pt} % was timenrr originally - now is times + +% ********************************************* +% -- End of block A -- +% +% +% -- Start of block B -- UPDATED FONT NAMES +% ********************************************* +% Gerry Murray 11/30/2006 +% ********************************************* +\newfont{\secfnt}{ptmb8t at 12pt} +\newfont{\secit}{ptmbi8t at 12pt} %13 Jan 00 gkmt +\newfont{\subsecfnt}{ptmri8t at 11pt} +\newfont{\subsecit}{ptmbi8t at 11pt} % +\newfont{\ttlfnt}{phvb8t at 18pt} +\newfont{\ttlit}{phvbo8t at 18pt} % GM 2/4/2000 +\newfont{\subttlfnt}{phvr8t at 14pt} +\newfont{\subttlit}{phvro8t at 14pt} % GM 2/4/2000 +\newfont{\subttlbf}{phvb8t at 14pt} % 13 Jan 00 gkmt +\newfont{\aufnt}{phvr8t at 12pt} +\newfont{\auit}{phvro8t at 12pt} % GM 2/4/2000 +\newfont{\affaddr}{phvr8t at 10pt} +\newfont{\affaddrit}{phvro8t at 10pt} % GM 2/4/2000 +\newfont{\eaddfnt}{phvr8t at 12pt} +\newfont{\ixpt}{ptmr8t at 9pt} +\newfont{\confname}{ptmri8t at 8pt} +\newfont{\crnotice}{ptmr8t at 8pt} +\newfont{\ninept}{ptmr8t at 9pt} +% +++++++++++++++++++++++++++++++++++++++++++++ +% -- End of block B -- + +%\def\email#1{{{\eaddfnt{\vskip 4pt#1}}}} +% If we have an email, inside a "shared affiliation" then we need the following instead +\def\email#1{{{\eaddfnt{\par #1}}}} % revised - GM - 11/30/2006 + +\def\addauthorsection{\ifnum\originalaucount>6 % was 3 - Gerry March 2007 + \section{Additional Authors}\the\addauthors + \fi} + +\newcount\savesection +\newcount\sectioncntr +\global\sectioncntr=1 + +\setcounter{secnumdepth}{3} + +\def\appendix{\par +\section*{APPENDIX} +\setcounter{section}{0} + \setcounter{subsection}{0} + \def\thesection{\Alph{section}} } + +\leftmargini 22.5pt +\leftmarginii 19.8pt % > \labelsep + width of '(m)' +\leftmarginiii 16.8pt % > \labelsep + width of 'vii.' +\leftmarginiv 15.3pt % > \labelsep + width of 'M.' +\leftmarginv 9pt +\leftmarginvi 9pt + +\leftmargin\leftmargini +\labelsep 4.5pt +\labelwidth\leftmargini\advance\labelwidth-\labelsep + +\def\@listI{\leftmargin\leftmargini \parsep 3.6pt plus 2pt minus 1pt% +\topsep 7.2pt plus 2pt minus 4pt% +\itemsep 3.6pt plus 2pt minus 1pt} + +\let\@listi\@listI +\@listi + +\def\@listii{\leftmargin\leftmarginii + \labelwidth\leftmarginii\advance\labelwidth-\labelsep + \topsep 3.6pt plus 2pt minus 1pt + \parsep 1.8pt plus 0.9pt minus 0.9pt + \itemsep \parsep} + +\def\@listiii{\leftmargin\leftmarginiii + \labelwidth\leftmarginiii\advance\labelwidth-\labelsep + \topsep 1.8pt plus 0.9pt minus 0.9pt + \parsep \z@ \partopsep 1pt plus 0pt minus 1pt + \itemsep \topsep} + +\def\@listiv{\leftmargin\leftmarginiv + \labelwidth\leftmarginiv\advance\labelwidth-\labelsep} + +\def\@listv{\leftmargin\leftmarginv + \labelwidth\leftmarginv\advance\labelwidth-\labelsep} + +\def\@listvi{\leftmargin\leftmarginvi + \labelwidth\leftmarginvi\advance\labelwidth-\labelsep} + +\def\labelenumi{\theenumi.} +\def\theenumi{\arabic{enumi}} + +\def\labelenumii{(\theenumii)} +\def\theenumii{\alph{enumii}} +\def\p@enumii{\theenumi} + +\def\labelenumiii{\theenumiii.} +\def\theenumiii{\roman{enumiii}} +\def\p@enumiii{\theenumi(\theenumii)} + +\def\labelenumiv{\theenumiv.} +\def\theenumiv{\Alph{enumiv}} +\def\p@enumiv{\p@enumiii\theenumiii} + +\def\labelitemi{$\bullet$} +\def\labelitemii{\bf --} +\def\labelitemiii{$\ast$} +\def\labelitemiv{$\cdot$} + +\def\verse{\let\\=\@centercr + \list{}{\itemsep\z@ \itemindent -1.5em\listparindent \itemindent + \rightmargin\leftmargin\advance\leftmargin 1.5em}\item[]} +\let\endverse\endlist + +\def\quotation{\list{}{\listparindent 1.5em + \itemindent\listparindent + \rightmargin\leftmargin \parsep 0pt plus 1pt}\item[]} +\let\endquotation=\endlist + +\def\quote{\list{}{\rightmargin\leftmargin}\item[]} +\let\endquote=\endlist + +\def\descriptionlabel#1{\hspace\labelsep \bf #1} +\def\description{\list{}{\labelwidth\z@ \itemindent-\leftmargin + \let\makelabel\descriptionlabel}} + +\let\enddescription\endlist + +\def\theequation{\arabic{equation}} + +\arraycolsep 4.5pt % Half the space between columns in an array environment. +\tabcolsep 5.4pt % Half the space between columns in a tabular environment. +\arrayrulewidth .5pt % Width of rules in array and tabular environment. % (was .4) updated Gerry March 20 2007 +\doublerulesep 1.8pt % Space between adjacent rules in array or tabular env. + +\tabbingsep \labelsep % Space used by the \' command. (See LaTeX manual.) + +\skip\@mpfootins =\skip\footins + +\fboxsep =2.7pt % Space left between box and text by \fbox and \framebox. +\fboxrule =.5pt % Width of rules in box made by \fbox and \framebox. % (was .4) updated Gerry March 20 2007 + +\def\thepart{\Roman{part}} % Roman numeral part numbers. +\def\thesection {\arabic{section}} +\def\thesubsection {\thesection.\arabic{subsection}} +%\def\thesubsubsection {\thesubsection.\arabic{subsubsection}} % GM 7/30/2002 +%\def\theparagraph {\thesubsubsection.\arabic{paragraph}} % GM 7/30/2002 +\def\thesubparagraph {\theparagraph.\arabic{subparagraph}} + +\def\@pnumwidth{1.55em} +\def\@tocrmarg {2.55em} +\def\@dotsep{4.5} +\setcounter{tocdepth}{3} + +%\def\tableofcontents{\@latexerr{\tableofcontents: Tables of contents are not +% allowed in the `acmconf' document style.}\@eha} + +\def\tableofcontents{\ClassError{% + \string\tableofcontents\space is not allowed in the `acmconf' document % January 2008 + style}\@eha} + +\def\l@part#1#2{\addpenalty{\@secpenalty} + \addvspace{2.25em plus 1pt} % space above part line + \begingroup + \@tempdima 3em % width of box holding part number, used by + \parindent \z@ \rightskip \@pnumwidth %% \numberline + \parfillskip -\@pnumwidth + {\large \bf % set line in \large boldface + \leavevmode % TeX command to enter horizontal mode. + #1\hfil \hbox to\@pnumwidth{\hss #2}}\par + \nobreak % Never break after part entry + \endgroup} + +\def\l@section#1#2{\addpenalty{\@secpenalty} % good place for page break + \addvspace{1.0em plus 1pt} % space above toc entry + \@tempdima 1.5em % width of box holding section number + \begingroup + \parindent \z@ \rightskip \@pnumwidth + \parfillskip -\@pnumwidth + \bf % Boldface. + \leavevmode % TeX command to enter horizontal mode. + \advance\leftskip\@tempdima %% added 5 Feb 88 to conform to + \hskip -\leftskip %% 25 Jan 88 change to \numberline + #1\nobreak\hfil \nobreak\hbox to\@pnumwidth{\hss #2}\par + \endgroup} + + +\def\l@subsection{\@dottedtocline{2}{1.5em}{2.3em}} +\def\l@subsubsection{\@dottedtocline{3}{3.8em}{3.2em}} +\def\l@paragraph{\@dottedtocline{4}{7.0em}{4.1em}} +\def\l@subparagraph{\@dottedtocline{5}{10em}{5em}} + +%\def\listoffigures{\@latexerr{\listoffigures: Lists of figures are not +% allowed in the `acmconf' document style.}\@eha} + +\def\listoffigures{\ClassError{% + \string\listoffigures\space is not allowed in the `acmconf' document % January 2008 + style}\@eha} + +\def\l@figure{\@dottedtocline{1}{1.5em}{2.3em}} + +%\def\listoftables{\@latexerr{\listoftables: Lists of tables are not +% allowed in the `acmconf' document style.}\@eha} +%\let\l@table\l@figure + +\def\listoftables{\ClassError{% + \string\listoftables\space is not allowed in the `acmconf' document % January 2008 + style}\@eha} + \let\l@table\l@figure + +\def\footnoterule{\kern-3\p@ + \hrule width .5\columnwidth % (was .4) updated Gerry March 20 2007 + \kern 2.6\p@} % The \hrule has default height of .4pt % (was .4) updated Gerry March 20 2007 +% ------ +\long\def\@makefntext#1{\noindent +%\hbox to .5em{\hss$^{\@thefnmark}$}#1} % original +\hbox to .5em{\hss\textsuperscript{\@thefnmark}}#1} % C. Clifton / GM Oct. 2nd. 2002 +% ------- + +\long\def\@maketntext#1{\noindent +#1} + +\long\def\@maketitlenotetext#1#2{\noindent + \hbox to 1.8em{\hss$^{#1}$}#2} + +\setcounter{topnumber}{2} +\def\topfraction{.7} +\setcounter{bottomnumber}{1} +\def\bottomfraction{.3} +\setcounter{totalnumber}{3} +\def\textfraction{.2} +\def\floatpagefraction{.5} +\setcounter{dbltopnumber}{2} +\def\dbltopfraction{.7} +\def\dblfloatpagefraction{.5} + +% +\long\def\@makecaption#1#2{ + \vskip \baselineskip + \setbox\@tempboxa\hbox{\textbf{#1: #2}} + \ifdim \wd\@tempboxa >\hsize % IF longer than one line: + \textbf{#1: #2}\par % THEN set as ordinary paragraph. + \else % ELSE center. + \hbox to\hsize{\hfil\box\@tempboxa\hfil}\par + \fi} + +% + +\long\def\@makecaption#1#2{ + \vskip 10pt + \setbox\@tempboxa\hbox{\textbf{#1: #2}} + \ifdim \wd\@tempboxa >\hsize % IF longer than one line: + \textbf{#1: #2}\par % THEN set as ordinary paragraph. + \else % ELSE center. + \hbox to\hsize{\hfil\box\@tempboxa\hfil} + \fi} + +\@ifundefined{figure}{\newcounter {figure}} % this is for LaTeX2e + +\def\fps@figure{tbp} +\def\ftype@figure{1} +\def\ext@figure{lof} +\def\fnum@figure{Figure \thefigure} +\def\figure{\@float{figure}} +%\let\endfigure\end@float +\def\endfigure{\end@float} % Gerry January 2008 +\@namedef{figure*}{\@dblfloat{figure}} +\@namedef{endfigure*}{\end@dblfloat} + +\@ifundefined{table}{\newcounter {table}} % this is for LaTeX2e + +\def\fps@table{tbp} +\def\ftype@table{2} +\def\ext@table{lot} +\def\fnum@table{Table \thetable} +\def\table{\@float{table}} +%\let\endtable\end@float +\def\endtable{\end@float} % Gerry January 2008 +\@namedef{table*}{\@dblfloat{table}} +\@namedef{endtable*}{\end@dblfloat} + +\newtoks\titleboxnotes +\newcount\titleboxnoteflag + +\def\maketitle{\par + \begingroup + \def\thefootnote{\fnsymbol{footnote}} + \def\@makefnmark{\hbox + to 0pt{$^{\@thefnmark}$\hss}} + \twocolumn[\@maketitle] +\@thanks + \endgroup + \setcounter{footnote}{0} + \let\maketitle\relax + \let\@maketitle\relax + \gdef\@thanks{}\gdef\@author{}\gdef\@title{}\gdef\@subtitle{}\let\thanks\relax + \@copyrightspace} + +%% CHANGES ON NEXT LINES +\newif\if@ll % to record which version of LaTeX is in use + +\expandafter\ifx\csname LaTeXe\endcsname\relax % LaTeX2.09 is used +\else% LaTeX2e is used, so set ll to true +\global\@lltrue +\fi + +\if@ll + \NeedsTeXFormat{LaTeX2e} + \ProvidesClass{sig-alternate} [2009/04/22 - V2.4 - based on acmproc.cls V1.3 <Nov. 30 '99>] + \RequirePackage{latexsym}% QUERY: are these two really needed? + \let\dooptions\ProcessOptions +\else + \let\dooptions\@options +\fi +%% END CHANGES + +\def\@height{height} +\def\@width{width} +\def\@minus{minus} +\def\@plus{plus} +\def\hb@xt@{\hbox to} +\newif\if@faircopy +\@faircopyfalse +\def\ds@faircopy{\@faircopytrue} + +\def\ds@preprint{\@faircopyfalse} + +\@twosidetrue +\@mparswitchtrue +\def\ds@draft{\overfullrule 5\p@} +%% CHANGE ON NEXT LINE +\dooptions + +\lineskip \p@ +\normallineskip \p@ +\def\baselinestretch{1} +\def\@ptsize{0} %needed for amssymbols.sty + +%% CHANGES ON NEXT LINES +\if@ll% allow use of old-style font change commands in LaTeX2e +\@maxdepth\maxdepth +% +\DeclareOldFontCommand{\rm}{\ninept\rmfamily}{\mathrm} +\DeclareOldFontCommand{\sf}{\normalfont\sffamily}{\mathsf} +\DeclareOldFontCommand{\tt}{\normalfont\ttfamily}{\mathtt} +\DeclareOldFontCommand{\bf}{\normalfont\bfseries}{\mathbf} +\DeclareOldFontCommand{\it}{\normalfont\itshape}{\mathit} +\DeclareOldFontCommand{\sl}{\normalfont\slshape}{\@nomath\sl} +\DeclareOldFontCommand{\sc}{\normalfont\scshape}{\@nomath\sc} +\DeclareRobustCommand*{\cal}{\@fontswitch{\relax}{\mathcal}} +\DeclareRobustCommand*{\mit}{\@fontswitch{\relax}{\mathnormal}} +\fi +% +\if@ll + \renewcommand{\rmdefault}{cmr} % was 'ttm' +% Note! I have also found 'mvr' to work ESPECIALLY well. +% Gerry - October 1999 +% You may need to change your LV1times.fd file so that sc is +% mapped to cmcsc - -for smallcaps -- that is if you decide +% to change {cmr} to {times} above. (Not recommended) + \renewcommand{\@ptsize}{} + \renewcommand{\normalsize}{% + \@setfontsize\normalsize\@ixpt{10.5\p@}%\ninept% + \abovedisplayskip 6\p@ \@plus2\p@ \@minus\p@ + \belowdisplayskip \abovedisplayskip + \abovedisplayshortskip 6\p@ \@minus 3\p@ + \belowdisplayshortskip 6\p@ \@minus 3\p@ + \let\@listi\@listI + } +\else + \def\@normalsize{%changed next to 9 from 10 + \@setsize\normalsize{9\p@}\ixpt\@ixpt + \abovedisplayskip 6\p@ \@plus2\p@ \@minus\p@ + \belowdisplayskip \abovedisplayskip + \abovedisplayshortskip 6\p@ \@minus 3\p@ + \belowdisplayshortskip 6\p@ \@minus 3\p@ + \let\@listi\@listI + }% +\fi +\if@ll + \newcommand\scriptsize{\@setfontsize\scriptsize\@viipt{8\p@}} + \newcommand\tiny{\@setfontsize\tiny\@vpt{6\p@}} + \newcommand\large{\@setfontsize\large\@xiipt{14\p@}} + \newcommand\Large{\@setfontsize\Large\@xivpt{18\p@}} + \newcommand\LARGE{\@setfontsize\LARGE\@xviipt{20\p@}} + \newcommand\huge{\@setfontsize\huge\@xxpt{25\p@}} + \newcommand\Huge{\@setfontsize\Huge\@xxvpt{30\p@}} +\else + \def\scriptsize{\@setsize\scriptsize{8\p@}\viipt\@viipt} + \def\tiny{\@setsize\tiny{6\p@}\vpt\@vpt} + \def\large{\@setsize\large{14\p@}\xiipt\@xiipt} + \def\Large{\@setsize\Large{18\p@}\xivpt\@xivpt} + \def\LARGE{\@setsize\LARGE{20\p@}\xviipt\@xviipt} + \def\huge{\@setsize\huge{25\p@}\xxpt\@xxpt} + \def\Huge{\@setsize\Huge{30\p@}\xxvpt\@xxvpt} +\fi +\normalsize + +% make aubox hsize/number of authors up to 3, less gutter +% then showbox gutter showbox gutter showbox -- GKMT Aug 99 +\newbox\@acmtitlebox +\def\@maketitle{\newpage + \null + \setbox\@acmtitlebox\vbox{% +\baselineskip 20pt +\vskip 2em % Vertical space above title. + \begin{center} + {\ttlfnt \@title\par} % Title set in 18pt Helvetica (Arial) bold size. + \vskip 1.5em % Vertical space after title. +%This should be the subtitle. +{\subttlfnt \the\subtitletext\par}\vskip 1.25em%\fi + {\baselineskip 16pt\aufnt % each author set in \12 pt Arial, in a + \lineskip .5em % tabular environment + \begin{tabular}[t]{c}\@author + \end{tabular}\par} + \vskip 1.5em % Vertical space after author. + \end{center}} + \dimen0=\ht\@acmtitlebox + \advance\dimen0 by -12.75pc\relax % Increased space for title box -- KBT + \unvbox\@acmtitlebox + \ifdim\dimen0<0.0pt\relax\vskip-\dimen0\fi} + + +\newcount\titlenotecount +\global\titlenotecount=0 +\newtoks\tntoks +\newtoks\tntokstwo +\newtoks\tntoksthree +\newtoks\tntoksfour +\newtoks\tntoksfive + +\def\abstract{ +\ifnum\titlenotecount>0 % was =1 + \insert\footins{% + \reset@font\footnotesize + \interlinepenalty\interfootnotelinepenalty + \splittopskip\footnotesep + \splitmaxdepth \dp\strutbox \floatingpenalty \@MM + \hsize\columnwidth \@parboxrestore + \protected@edef\@currentlabel{% + }% + \color@begingroup +\ifnum\titlenotecount=1 + \@maketntext{% + \raisebox{4pt}{$\ast$}\rule\z@\footnotesep\ignorespaces\the\tntoks\@finalstrut\strutbox}% +\fi +\ifnum\titlenotecount=2 + \@maketntext{% + \raisebox{4pt}{$\ast$}\rule\z@\footnotesep\ignorespaces\the\tntoks\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\dagger$}\rule\z@\footnotesep\ignorespaces\the\tntokstwo\@finalstrut\strutbox}% +\fi +\ifnum\titlenotecount=3 + \@maketntext{% + \raisebox{4pt}{$\ast$}\rule\z@\footnotesep\ignorespaces\the\tntoks\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\dagger$}\rule\z@\footnotesep\ignorespaces\the\tntokstwo\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\ddagger$}\rule\z@\footnotesep\ignorespaces\the\tntoksthree\@finalstrut\strutbox}% +\fi +\ifnum\titlenotecount=4 + \@maketntext{% + \raisebox{4pt}{$\ast$}\rule\z@\footnotesep\ignorespaces\the\tntoks\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\dagger$}\rule\z@\footnotesep\ignorespaces\the\tntokstwo\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\ddagger$}\rule\z@\footnotesep\ignorespaces\the\tntoksthree\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\S$}\rule\z@\footnotesep\ignorespaces\the\tntoksfour\@finalstrut\strutbox}% +\fi +\ifnum\titlenotecount=5 + \@maketntext{% + \raisebox{4pt}{$\ast$}\rule\z@\footnotesep\ignorespaces\the\tntoks\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\dagger$}\rule\z@\footnotesep\ignorespaces\the\tntokstwo\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\ddagger$}\rule\z@\footnotesep\ignorespaces\the\tntoksthree\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\S$}\rule\z@\footnotesep\ignorespaces\the\tntoksfour\par\@finalstrut\strutbox}% +\@maketntext{% + \raisebox{4pt}{$\P$}\rule\z@\footnotesep\ignorespaces\the\tntoksfive\@finalstrut\strutbox}% +\fi + \color@endgroup} %g} +\fi +\setcounter{footnote}{0} +\section*{ABSTRACT}\normalsize%\ninept +} + +\def\endabstract{\if@twocolumn\else\endquotation\fi} + +\def\keywords{\if@twocolumn +\section*{Keywords} +\else \small +\quotation +\fi} + +\def\terms{\if@twocolumn +\section*{General Terms} +\else \small +\quotation +\fi} + +% -- Classification needs to be a bit smart due to optionals - Gerry/Georgia November 2nd. 1999 +\newcount\catcount +\global\catcount=1 + +\def\category#1#2#3{% +\ifnum\catcount=1 +\section*{Categories and Subject Descriptors} +\advance\catcount by 1\else{\unskip; }\fi + \@ifnextchar [{\@category{#1}{#2}{#3}}{\@category{#1}{#2}{#3}[]}% +} + +\def\@category#1#2#3[#4]{% + \begingroup + \let\and\relax + #1 [\textbf{#2}]% + \if!#4!% + \if!#3!\else : #3\fi + \else + :\space + \if!#3!\else #3\kern\z@---\hskip\z@\fi + \textit{#4}% + \fi + \endgroup +} +% + +%%% This section (written by KBT) handles the 1" box in the lower left +%%% corner of the left column of the first page by creating a picture, +%%% and inserting the predefined string at the bottom (with a negative +%%% displacement to offset the space allocated for a non-existent +%%% caption). +%%% +\newtoks\copyrightnotice +\def\ftype@copyrightbox{8} +\def\@copyrightspace{ +\@float{copyrightbox}[b] +\begin{center} +\setlength{\unitlength}{1pc} +\begin{picture}(20,6) %Space for copyright notice +\put(0,-0.95){\crnotice{\@toappear}} +\end{picture} +\end{center} +\end@float} + +\def\@toappear{} % Default setting blank - commands below change this. +\long\def\toappear#1{\def\@toappear{\parbox[b]{20pc}{\baselineskip 9pt#1}}} +\def\toappearbox#1{\def\@toappear{\raisebox{5pt}{\framebox[20pc]{\parbox[b]{19pc}{#1}}}}} + +\newtoks\conf +\newtoks\confinfo +\def\conferenceinfo#1#2{\global\conf={#1}\global\confinfo{#2}} + + +%\def\marginpar{\@latexerr{The \marginpar command is not allowed in the +% `acmconf' document style.}\@eha} + +\def\marginpar{\ClassError{% + \string\marginpar\space is not allowed in the `acmconf' document % January 2008 + style}\@eha} + +\mark{{}{}} % Initializes TeX's marks + +\def\today{\ifcase\month\or + January\or February\or March\or April\or May\or June\or + July\or August\or September\or October\or November\or December\fi + \space\number\day, \number\year} + +\def\@begintheorem#1#2{% + \parskip 0pt % GM July 2000 (for tighter spacing) + \trivlist + \item[% + \hskip 10\p@ + \hskip \labelsep + {{\sc #1}\hskip 5\p@\relax#2.}% + ] + \it +} +\def\@opargbegintheorem#1#2#3{% + \parskip 0pt % GM July 2000 (for tighter spacing) + \trivlist + \item[% + \hskip 10\p@ + \hskip \labelsep + {\sc #1\ #2\ % This mod by Gerry to enumerate corollaries + \setbox\@tempboxa\hbox{(#3)} % and bracket the 'corollary title' + \ifdim \wd\@tempboxa>\z@ % and retain the correct numbering of e.g. theorems + \hskip 5\p@\relax % if they occur 'around' said corollaries. + \box\@tempboxa % Gerry - Nov. 1999. + \fi.}% + ] + \it +} +\newif\if@qeded +\global\@qededfalse + +% -- original +%\def\proof{% +% \vspace{-\parskip} % GM July 2000 (for tighter spacing) +% \global\@qededfalse +% \@ifnextchar[{\@xproof}{\@proof}% +%} +% -- end of original + +% (JSS) Fix for vertical spacing bug - Gerry Murray July 30th. 2002 +\def\proof{% +\vspace{-\lastskip}\vspace{-\parsep}\penalty-51% +\global\@qededfalse +\@ifnextchar[{\@xproof}{\@proof}% +} + +\def\endproof{% + \if@qeded\else\qed\fi + \endtrivlist +} +\def\@proof{% + \trivlist + \item[% + \hskip 10\p@ + \hskip \labelsep + {\sc Proof.}% + ] + \ignorespaces +} +\def\@xproof[#1]{% + \trivlist + \item[\hskip 10\p@\hskip \labelsep{\sc Proof #1.}]% + \ignorespaces +} +\def\qed{% + \unskip + \kern 10\p@ + \begingroup + \unitlength\p@ + \linethickness{.4\p@}% + \framebox(6,6){}% + \endgroup + \global\@qededtrue +} + +\def\newdef#1#2{% + \expandafter\@ifdefinable\csname #1\endcsname + {\@definecounter{#1}% + \expandafter\xdef\csname the#1\endcsname{\@thmcounter{#1}}% + \global\@namedef{#1}{\@defthm{#1}{#2}}% + \global\@namedef{end#1}{\@endtheorem}% + }% +} +\def\@defthm#1#2{% + \refstepcounter{#1}% + \@ifnextchar[{\@ydefthm{#1}{#2}}{\@xdefthm{#1}{#2}}% +} +\def\@xdefthm#1#2{% + \@begindef{#2}{\csname the#1\endcsname}% + \ignorespaces +} +\def\@ydefthm#1#2[#3]{% + \trivlist + \item[% + \hskip 10\p@ + \hskip \labelsep + {\it #2% +% \savebox\@tempboxa{#3}% + \saveb@x\@tempboxa{#3}% % January 2008 + \ifdim \wd\@tempboxa>\z@ + \ \box\@tempboxa + \fi.% + }]% + \ignorespaces +} +\def\@begindef#1#2{% + \trivlist + \item[% + \hskip 10\p@ + \hskip \labelsep + {\it #1\ \rm #2.}% + ]% +} +\def\theequation{\arabic{equation}} + +\newcounter{part} +\newcounter{section} +\newcounter{subsection}[section] +\newcounter{subsubsection}[subsection] +\newcounter{paragraph}[subsubsection] +\def\thepart{\Roman{part}} +\def\thesection{\arabic{section}} +\def\thesubsection{\thesection.\arabic{subsection}} +\def\thesubsubsection{\thesubsection.\arabic{subsubsection}} %removed \subsecfnt 29 July 2002 gkmt +\def\theparagraph{\thesubsubsection.\arabic{paragraph}} %removed \subsecfnt 29 July 2002 gkmt +\newif\if@uchead +\@ucheadfalse + +%% CHANGES: NEW NOTE +%% NOTE: OK to use old-style font commands below, since they were +%% suitably redefined for LaTeX2e +%% END CHANGES +\setcounter{secnumdepth}{3} +\def\part{% + \@startsection{part}{9}{\z@}{-10\p@ \@plus -4\p@ \@minus -2\p@} + {4\p@}{\normalsize\@ucheadtrue}% +} +\def\section{% + \@startsection{section}{1}{\z@}{-10\p@ \@plus -4\p@ \@minus -2\p@}% GM + {4\p@}{\baselineskip 14pt\secfnt\@ucheadtrue}% +} + +\def\subsection{% + \@startsection{subsection}{2}{\z@}{-8\p@ \@plus -2\p@ \@minus -\p@} + {4\p@}{\secfnt}% +} +\def\subsubsection{% + \@startsection{subsubsection}{3}{\z@}{-8\p@ \@plus -2\p@ \@minus -\p@}% + {4\p@}{\subsecfnt}% +} +%\def\paragraph{% +% \vskip 12pt\@startsection{paragraph}{3}{\z@}{6\p@ \@plus \p@}% original +% {-5\p@}{\subsecfnt}% +%} +% If one wants sections, subsections and subsubsections numbered, +% but not paragraphs, one usually sets secnumepth to 3. +% For that, the "depth" of paragraphs must be given correctly +% in the definition (``4'' instead of ``3'' as second argument +% of @startsection): +\def\paragraph{% + \vskip 12pt\@startsection{paragraph}{4}{\z@}{6\p@ \@plus \p@}% % GM and Wolfgang May - 11/30/06 + {-5\p@}{\subsecfnt}% +} +\let\@period=. +\def\@startsection#1#2#3#4#5#6{% + \if@noskipsec %gkmt, 11 aug 99 + \global\let\@period\@empty + \leavevmode + \global\let\@period.% + \fi + \par % + \@tempskipa #4\relax + \@afterindenttrue + \ifdim \@tempskipa <\z@ + \@tempskipa -\@tempskipa + \@afterindentfalse + \fi + \if@nobreak + \everypar{}% + \else + \addpenalty\@secpenalty + \addvspace\@tempskipa + \fi +\parskip=0pt % GM July 2000 (non numbered) section heads + \@ifstar + {\@ssect{#3}{#4}{#5}{#6}} + {\@dblarg{\@sect{#1}{#2}{#3}{#4}{#5}{#6}}}% +} +\def\@sect#1#2#3#4#5#6[#7]#8{% + \ifnum #2>\c@secnumdepth + \let\@svsec\@empty + \else + \refstepcounter{#1}% + \edef\@svsec{% + \begingroup + %\ifnum#2>2 \noexpand\rm \fi % changed to next 29 July 2002 gkmt + \ifnum#2>2 \noexpand#6 \fi + \csname the#1\endcsname + \endgroup + \ifnum #2=1\relax .\fi + \hskip 1em + }% + \fi + \@tempskipa #5\relax + \ifdim \@tempskipa>\z@ + \begingroup + #6\relax + \@hangfrom{\hskip #3\relax\@svsec}% + \begingroup + \interlinepenalty \@M + \if@uchead + \uppercase{#8}% + \else + #8% + \fi + \par + \endgroup + \endgroup + \csname #1mark\endcsname{#7}% + \vskip -12pt %gkmt, 11 aug 99 and GM July 2000 (was -14) - numbered section head spacing +\addcontentsline{toc}{#1}{% + \ifnum #2>\c@secnumdepth \else + \protect\numberline{\csname the#1\endcsname}% + \fi + #7% + }% + \else + \def\@svsechd{% + #6% + \hskip #3\relax + \@svsec + \if@uchead + \uppercase{#8}% + \else + #8% + \fi + \csname #1mark\endcsname{#7}% + \addcontentsline{toc}{#1}{% + \ifnum #2>\c@secnumdepth \else + \protect\numberline{\csname the#1\endcsname}% + \fi + #7% + }% + }% + \fi + \@xsect{#5}\hskip 1pt + \par +} +\def\@xsect#1{% + \@tempskipa #1\relax + \ifdim \@tempskipa>\z@ + \par + \nobreak + \vskip \@tempskipa + \@afterheading + \else + \global\@nobreakfalse + \global\@noskipsectrue + \everypar{% + \if@noskipsec + \global\@noskipsecfalse + \clubpenalty\@M + \hskip -\parindent + \begingroup + \@svsechd + \@period + \endgroup + \unskip + \@tempskipa #1\relax + \hskip -\@tempskipa + \else + \clubpenalty \@clubpenalty + \everypar{}% + \fi + }% + \fi + \ignorespaces +} +\def\@trivlist{% + \@topsepadd\topsep + \if@noskipsec + \global\let\@period\@empty + \leavevmode + \global\let\@period.% + \fi + \ifvmode + \advance\@topsepadd\partopsep + \else + \unskip + \par + \fi + \if@inlabel + \@noparitemtrue + \@noparlisttrue + \else + \@noparlistfalse + \@topsep\@topsepadd + \fi + \advance\@topsep \parskip + \leftskip\z@skip + \rightskip\@rightskip + \parfillskip\@flushglue + \@setpar{\if@newlist\else{\@@par}\fi} + \global\@newlisttrue + \@outerparskip\parskip +} + +%%% Actually, 'abbrev' works just fine as the default +%%% Bibliography style. + +\typeout{Using 'Abbrev' bibliography style} +\newcommand\bibyear[2]{% + \unskip\quad\ignorespaces#1\unskip + \if#2..\quad \else \quad#2 \fi +} +\newcommand{\bibemph}[1]{{\em#1}} +\newcommand{\bibemphic}[1]{{\em#1\/}} +\newcommand{\bibsc}[1]{{\sc#1}} +\def\@normalcite{% + \def\@cite##1##2{[##1\if@tempswa , ##2\fi]}% +} +\def\@citeNB{% + \def\@cite##1##2{##1\if@tempswa , ##2\fi}% +} +\def\@citeRB{% + \def\@cite##1##2{##1\if@tempswa , ##2\fi]}% +} +\def\start@cite#1#2{% + \edef\citeauthoryear##1##2##3{% + ###1% + \ifnum#2=\z@ \else\ ###2\fi + }% + \ifnum#1=\thr@@ + \let\@@cite\@citeyear + \else + \let\@@cite\@citenormal + \fi + \@ifstar{\@citeNB\@@cite}{\@normalcite\@@cite}% +} +%\def\cite{\start@cite23} +\DeclareRobustCommand\cite{\start@cite23} % January 2008 +\def\citeNP{\cite*} % No Parentheses e.g. 5 +%\def\citeA{\start@cite10} +\DeclareRobustCommand\citeA{\start@cite10} % January 2008 +\def\citeANP{\citeA*} +%\def\shortcite{\start@cite23} +\DeclareRobustCommand\shortcite{\start@cite23} % January 2008 +\def\shortciteNP{\shortcite*} +%\def\shortciteA{\start@cite20} +\DeclareRobustCommand\shortciteA{\start@cite20} % January 2008 +\def\shortciteANP{\shortciteA*} +%\def\citeyear{\start@cite30} +\DeclareRobustCommand\citeyear{\start@cite30} % January 2008 +\def\citeyearNP{\citeyear*} +%\def\citeN{% +\DeclareRobustCommand\citeN{% % January 2008 + \@citeRB + \def\citeauthoryear##1##2##3{##1\ [##3% + \def\reserved@a{##1}% + \def\citeauthoryear####1####2####3{% + \def\reserved@b{####1}% + \ifx\reserved@a\reserved@b + ####3% + \else + \errmessage{Package acmart Error: author mismatch + in \string\citeN^^J^^J% + See the acmart package documentation for explanation}% + \fi + }% + }% + \@ifstar\@citeyear\@citeyear +} +%\def\shortciteN{% +\DeclareRobustCommand\shortciteN{% % January 2008 + \@citeRB + \def\citeauthoryear##1##2##3{##2\ [##3% + \def\reserved@a{##2}% + \def\citeauthoryear####1####2####3{% + \def\reserved@b{####2}% + \ifx\reserved@a\reserved@b + ####3% + \else + \errmessage{Package acmart Error: author mismatch + in \string\shortciteN^^J^^J% + See the acmart package documentation for explanation}% + \fi + }% + }% + \@ifstar\@citeyear\@citeyear % GM July 2000 +} + +\def\@citenormal{% + \@ifnextchar [{\@tempswatrue\@citex;}% +% original {\@tempswafalse\@citex,[]}% was ; Gerry 2/24/00 +{\@tempswafalse\@citex[]}% % GERRY FIX FOR BABEL 3/20/2009 +} + +\def\@citeyear{% + \@ifnextchar [{\@tempswatrue\@citex,}% +% original {\@tempswafalse\@citex,[]}% +{\@tempswafalse\@citex[]}% % GERRY FIX FOR BABEL 3/20/2009 +} + +\def\@citex#1[#2]#3{% + \let\@citea\@empty + \@cite{% + \@for\@citeb:=#3\do{% + \@citea +% original \def\@citea{#1 }% + \def\@citea{#1, }% % GERRY FIX FOR BABEL 3/20/2009 -- SO THAT YOU GET [1, 2] IN THE BODY TEXT + \edef\@citeb{\expandafter\@iden\@citeb}% + \if@filesw + \immediate\write\@auxout{\string\citation{\@citeb}}% + \fi + \@ifundefined{b@\@citeb}{% + {\bf ?}% + \@warning{% + Citation `\@citeb' on page \thepage\space undefined% + }% + }% + {\csname b@\@citeb\endcsname}% + }% + }{#2}% +} +%\let\@biblabel\@gobble % Dec. 2008 - Gerry +% ---- +\def\@biblabelnum#1{[#1]} % Gerry's solution #1 - for Natbib -- April 2009 +\let\@biblabel=\@biblabelnum % Gerry's solution #1 - for Natbib -- April 2009 +\def\newblock{\relax} % Gerry Dec. 2008 +% --- +\newdimen\bibindent +\setcounter{enumi}{1} +\bibindent=0em +\def\thebibliography#1{% +\ifnum\addauflag=0\addauthorsection\global\addauflag=1\fi + \section[References]{% <=== OPTIONAL ARGUMENT ADDED HERE + {References} % was uppercased but this affects pdf bookmarks (SP/GM October 2004) + {\vskip -9pt plus 1pt} % GM Nov. 2006 / GM July 2000 (for somewhat tighter spacing) + \@mkboth{{\refname}}{{\refname}}% + }% + \list{[\arabic{enumi}]}{% + \settowidth\labelwidth{[#1]}% + \leftmargin\labelwidth + \advance\leftmargin\labelsep + \advance\leftmargin\bibindent + \parsep=0pt\itemsep=1pt % GM July 2000 + \itemindent -\bibindent + \listparindent \itemindent + \usecounter{enumi} + }% + \let\newblock\@empty + \raggedright % GM July 2000 + \sloppy + \sfcode`\.=1000\relax +} + + +\gdef\balancecolumns +{\vfill\eject +\global\@colht=\textheight +\global\ht\@cclv=\textheight +} + +\newcount\colcntr +\global\colcntr=0 +%\newbox\savebox +\newbox\saveb@x % January 2008 + +\gdef \@makecol {% +\global\advance\colcntr by 1 +\ifnum\colcntr>2 \global\colcntr=1\fi + \ifvoid\footins + \setbox\@outputbox \box\@cclv + \else + \setbox\@outputbox \vbox{% +\boxmaxdepth \@maxdepth + \@tempdima\dp\@cclv + \unvbox \@cclv + \vskip-\@tempdima + \vskip \skip\footins + \color@begingroup + \normalcolor + \footnoterule + \unvbox \footins + \color@endgroup + }% + \fi + \xdef\@freelist{\@freelist\@midlist}% + \global \let \@midlist \@empty + \@combinefloats + \ifvbox\@kludgeins + \@makespecialcolbox + \else + \setbox\@outputbox \vbox to\@colht {% +\@texttop + \dimen@ \dp\@outputbox + \unvbox \@outputbox + \vskip -\dimen@ + \@textbottom + }% + \fi + \global \maxdepth \@maxdepth +} +\def\titlenote{\@ifnextchar[\@xtitlenote{\stepcounter\@mpfn +\global\advance\titlenotecount by 1 +\ifnum\titlenotecount=1 + \raisebox{9pt}{$\ast$} +\fi +\ifnum\titlenotecount=2 + \raisebox{9pt}{$\dagger$} +\fi +\ifnum\titlenotecount=3 + \raisebox{9pt}{$\ddagger$} +\fi +\ifnum\titlenotecount=4 +\raisebox{9pt}{$\S$} +\fi +\ifnum\titlenotecount=5 +\raisebox{9pt}{$\P$} +\fi + \@titlenotetext +}} + +\long\def\@titlenotetext#1{\insert\footins{% +\ifnum\titlenotecount=1\global\tntoks={#1}\fi +\ifnum\titlenotecount=2\global\tntokstwo={#1}\fi +\ifnum\titlenotecount=3\global\tntoksthree={#1}\fi +\ifnum\titlenotecount=4\global\tntoksfour={#1}\fi +\ifnum\titlenotecount=5\global\tntoksfive={#1}\fi + \reset@font\footnotesize + \interlinepenalty\interfootnotelinepenalty + \splittopskip\footnotesep + \splitmaxdepth \dp\strutbox \floatingpenalty \@MM + \hsize\columnwidth \@parboxrestore + \protected@edef\@currentlabel{% + }% + \color@begingroup + \color@endgroup}} + +%%%%%%%%%%%%%%%%%%%%%%%%% +\ps@plain +\baselineskip=11pt +\let\thepage\relax % For NO page numbers - GM Nov. 30th. 1999 and July 2000 +\def\setpagenumber#1{\global\setcounter{page}{#1}} +%\pagenumbering{arabic} % Arabic page numbers GM July 2000 +\twocolumn % Double column. +\flushbottom % Even bottom -- alas, does not balance columns at end of document +\pagestyle{plain} + +% Need Copyright Year and Copyright Data to be user definable (in .tex file). +% Gerry Nov. 30th. 1999 +\newtoks\copyrtyr +\newtoks\acmcopyr +\newtoks\boilerplate +\global\acmcopyr={X-XXXXX-XX-X/XX/XX} % Default - 5/11/2001 *** Gerry +\global\copyrtyr={200X} % Default - 3/3/2003 *** Gerry +\def\CopyrightYear#1{\global\copyrtyr{#1}} +\def\crdata#1{\global\acmcopyr{#1}} +\def\permission#1{\global\boilerplate{#1}} +% +\global\boilerplate={Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee.} +\newtoks\copyrightetc +\global\copyrightetc{Copyright \the\copyrtyr\ ACM \the\acmcopyr\ ...\$10.00} +\toappear{\the\boilerplate\par +{\confname{\the\conf}} \the\confinfo\par \the\copyrightetc.} +%\DeclareFixedFont{\altcrnotice}{OT1}{tmr}{m}{n}{8} % << patch needed for accenting e.g. Montreal - Gerry, May 2007 +%\DeclareFixedFont{\altconfname}{OT1}{tmr}{m}{it}{8} % << patch needed for accenting in italicized confname - Gerry, May 2007 +% +%{\altconfname{{\the\conf}}} {\altcrnotice\the\confinfo\par} \the\copyrightetc.} % << Gerry, May 2007 +% +% The following section (i.e. 3 .sty inclusions) was added in May 2007 so as to fix the problems that many +% authors were having with accents. Sometimes accents would occur, but the letter-character would be of a different +% font. Conversely the letter-character font would be correct but, e.g. a 'bar' would appear superimposed on the +% character instead of, say, an unlaut/diaresis. Sometimes the letter-character would NOT appear at all. +% Using [T1]{fontenc} outright was not an option as this caused 99% of the authors to 'produce' a Type-3 (bitmapped) +% PDF file - useless for production. +% +% For proper (font) accenting we NEED these packages to be part of the .cls file i.e. 'ae', 'aecompl' and 'aeguil' +% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +%% This is file `ae.sty' +\def\fileversion{1.3} +\def\filedate{2001/02/12} +\NeedsTeXFormat{LaTeX2e} +%\ProvidesPackage{ae}[\filedate\space\fileversion\space % GM +% Almost European Computer Modern] % GM - keeping the log file clean(er) +\newif\if@ae@slides \@ae@slidesfalse +\DeclareOption{slides}{\@ae@slidestrue} +\ProcessOptions +\fontfamily{aer} +\RequirePackage[T1]{fontenc} +\if@ae@slides + \renewcommand{\sfdefault}{laess} + \renewcommand{\rmdefault}{laess} % no roman + \renewcommand{\ttdefault}{laett} +\else + \renewcommand{\sfdefault}{aess} + \renewcommand{\rmdefault}{aer} + \renewcommand{\ttdefault}{aett} +\fi +\endinput +%% +%% End of file `ae.sty'. +% +% +\def\fileversion{0.9} +\def\filedate{1998/07/23} +\NeedsTeXFormat{LaTeX2e} +%\ProvidesPackage{aecompl}[\filedate\space\fileversion\space % GM +%T1 Complements for AE fonts (D. Roegel)] % GM -- keeping the log file clean(er) + +\def\@ae@compl#1{{\fontencoding{T1}\fontfamily{cmr}\selectfont\symbol{#1}}} +\def\guillemotleft{\@ae@compl{19}} +\def\guillemotright{\@ae@compl{20}} +\def\guilsinglleft{\@ae@compl{14}} +\def\guilsinglright{\@ae@compl{15}} +\def\TH{\@ae@compl{222}} +\def\NG{\@ae@compl{141}} +\def\ng{\@ae@compl{173}} +\def\th{\@ae@compl{254}} +\def\DJ{\@ae@compl{208}} +\def\dj{\@ae@compl{158}} +\def\DH{\@ae@compl{208}} +\def\dh{\@ae@compl{240}} +\def\@perthousandzero{\@ae@compl{24}} +\def\textperthousand{\%\@perthousandzero} +\def\textpertenthousand{\%\@perthousandzero\@perthousandzero} +\endinput +% +% +%% This is file `aeguill.sty' +% This file gives french guillemets (and not guillemots!) +% built with the Polish CMR fonts (default), WNCYR fonts, the LASY fonts +% or with the EC fonts. +% This is useful in conjunction with the ae package +% (this package loads the ae package in case it has not been loaded) +% and with or without the french(le) package. +% +% In order to get the guillemets, it is necessary to either type +% \guillemotleft and \guillemotright, or to use an 8 bit encoding +% (such as ISO-Latin1) which selects these two commands, +% or, if you use the french package (but not the frenchle package), +% to type << or >>. +% +% By default, you get the Polish CMR guillemets; if this package is loaded +% with the `cm' option, you get the LASY guillemets; with `ec,' you +% get the EC guillemets, and with `cyr,' you get the cyrillic guillemets. +% +% In verbatim mode, you always get the EC/TT guillemets. +% +% The default option is interesting in conjunction with PDF, +% because there is a Type 1 version of the Polish CMR fonts +% and these guillemets are very close in shape to the EC guillemets. +% There are no free Type 1 versions of the EC fonts. +% +% Support for Polish CMR guillemets was kindly provided by +% Rolf Niepraschk <niepraschk@ptb.de> in version 0.99 (2000/05/22). +% Bernd Raichle provided extensive simplifications to the code +% for version 1.00. +% +% This package is released under the LPPL. +% +% Changes: +% Date version +% 2001/04/12 1.01 the frenchle and french package are now distinguished. +% +\def\fileversion{1.01} +\def\filedate{2001/04/12} +\NeedsTeXFormat{LaTeX2e} +%\ProvidesPackage{aeguill}[2001/04/12 1.01 % % GM +%AE fonts with french guillemets (D. Roegel)] % GM - keeping the log file clean(er) +%\RequirePackage{ae} % GM May 2007 - already embedded here + +\newcommand{\@ae@switch}[4]{#4} +\DeclareOption{ec}{\renewcommand\@ae@switch[4]{#1}} +\DeclareOption{cm}{\renewcommand\@ae@switch[4]{#2}} +\DeclareOption{cyr}{\renewcommand\@ae@switch[4]{#3}} +\DeclareOption{pl}{\renewcommand\@ae@switch[4]{#4}} +\ExecuteOptions{pl} +\ProcessOptions + +% +% Load necessary packages +% +\@ae@switch{% ec + % do nothing +}{% cm + \RequirePackage{latexsym}% GM - May 2007 - already 'mentioned as required' up above +}{% cyr + \RequirePackage[OT2,T1]{fontenc}% +}{% pl + \RequirePackage[OT4,T1]{fontenc}% +} + +% The following command will be compared to \frenchname, +% as defined in french.sty and frenchle.sty. +\def\aeguillfrenchdefault{french}% + +\let\guill@verbatim@font\verbatim@font +\def\verbatim@font{\guill@verbatim@font\ecguills{cmtt}% + \let\guillemotleft\@oguills\let\guillemotright\@fguills} + +\begingroup \catcode`\<=13 \catcode`\>=13 +\def\x{\endgroup + \def\ae@lfguill{<<}% + \def\ae@rfguill{>>}% +}\x + +\newcommand{\ecguills}[1]{% + \def\selectguillfont{\fontencoding{T1}\fontfamily{#1}\selectfont}% + \def\@oguills{{\selectguillfont\symbol{19}}}% + \def\@fguills{{\selectguillfont\symbol{20}}}% + } + +\newcommand{\aeguills}{% + \ae@guills + % We redefine \guillemotleft and \guillemotright + % in order to catch them when they are used + % with \DeclareInputText (in latin1.def for instance) + % We use \auxWARNINGi as a safe indicator that french.sty is used. + \gdef\guillemotleft{\ifx\auxWARNINGi\undefined + \@oguills % neither french.sty nor frenchle.sty + \else + \ifx\aeguillfrenchdefault\frenchname + \ae@lfguill % french.sty + \else + \@oguills % frenchle.sty + \fi + \fi}% + \gdef\guillemotright{\ifx\auxWARNINGi\undefined + \@fguills % neither french.sty nor frenchle.sty + \else + \ifx\aeguillfrenchdefault\frenchname + \ae@rfguill % french.sty + \else + \@fguills % frenchle.sty + \fi + \fi}% + } + +% +% Depending on the class option +% define the internal command \ae@guills +\@ae@switch{% ec + \newcommand{\ae@guills}{% + \ecguills{cmr}}% +}{% cm + \newcommand{\ae@guills}{% + \def\selectguillfont{\fontencoding{U}\fontfamily{lasy}% + \fontseries{m}\fontshape{n}\selectfont}% + \def\@oguills{\leavevmode\nobreak + \hbox{\selectguillfont (\kern-.20em(\kern.20em}\nobreak}% + \def\@fguills{\leavevmode\nobreak + \hbox{\selectguillfont \kern.20em)\kern-.2em)}% + \ifdim\fontdimen\@ne\font>\z@\/\fi}}% +}{% cyr + \newcommand{\ae@guills}{% + \def\selectguillfont{\fontencoding{OT2}\fontfamily{wncyr}\selectfont}% + \def\@oguills{{\selectguillfont\symbol{60}}}% + \def\@fguills{{\selectguillfont\symbol{62}}}} +}{% pl + \newcommand{\ae@guills}{% + \def\selectguillfont{\fontencoding{OT4}\fontfamily{cmr}\selectfont}% + \def\@oguills{{\selectguillfont\symbol{174}}}% + \def\@fguills{{\selectguillfont\symbol{175}}}} +} + + +\AtBeginDocument{% + \ifx\GOfrench\undefined + \aeguills + \else + \let\aeguill@GOfrench\GOfrench + \gdef\GOfrench{\aeguill@GOfrench \aeguills}% + \fi + } + +\endinput +% + diff --git a/articles/ui/ui_short.tex b/articles/ui/ui_short.tex new file mode 100644 index 000000000..f1b37b970 --- /dev/null +++ b/articles/ui/ui_short.tex @@ -0,0 +1,260 @@ + +\title{Taler: \\ Usable, privacy-preserving payments for the Web} + \author{ + Jeffrey Burdges \\ \and + Florian Dold \\ \and + Christian Grothoff \\ \and + Marcello Stanisci +} +\date{\today} + +\documentclass[twoside,letterpaper]{sigalternate} +\usepackage[margin=1in]{geometry} +\usepackage[utf8]{inputenc} +\usepackage{url} +\usepackage{tikz} +\usepackage{eurosym} +\usepackage{listings} +\usepackage{graphicx} +\usepackage{wrapfig} +\usepackage{caption} +\usepackage{subcaption} +\usepackage{url} +%\usepackage{dblfloatfix} + +\usetikzlibrary{shapes,arrows} +\usetikzlibrary{positioning} +\usetikzlibrary{calc} + +\begin{document} +\maketitle + +\section{System overview} + +Content and services provided on the internet, such as reading a blog post or +sending an email, tend to be of very small monetary value compared to +traditional financial transactions. Currently the majority of online offerings +are financed via advertisements. Any alternatives must reduce the mental +and technical overheads of existing payment systems to handle micro-payments. +Addressing this problem is urgent: ad-blocking technology is eroding +advertising, and the Big Data business model where citizens pay with their +private information in combination with the deep state hastens our society's +regression towards post-democracy~\cite{rms2013democracy}. + +Taler is a new electronic online payment system that provides +anonymity for customers. Here, {\em anonymous} simply means that the +payment system does not require any personal information from the +customer, and that different transactions by the same customer are +unlinkable. For strong anonymity, Taler usually needs to be used in +combination with existing techniques (such as~\cite{apod}) to avoid +circumstances leaking information about the customer's identity. The +fact that the user does not need to authenticate and that the merchant +thus never learns sensitive personal information about the customer +improves usability and security: the payment process is simplified, the +merchant's security requirements are dramatically reduced and the customer's +risk of identity theft does not accumulate with every (micro-)payment. + +Taler uses blind signatures~\cite{chaum1983blind} to create digital +coins, and a novel ``refresh'' protocol to allow giving change and +refunds while maintaining unlinkability. We will not go into the +details of Taler's cryptographic protocols here\footnote{Full +documentation at \url{https://api.taler.net/}} and instead focus on the +high-level concepts to explain how the system works from the +perspective of customers and merchants in the Taler +system (Figure~\ref{fig:system}). +% "... and how it contributes to customer privacy"? + +\begin{figure}[t!] +\centering +\begin{tikzpicture} + \tikzstyle{def} = [node distance=3em and 5em, inner sep=1em, outer sep=.3em]; + \node (origin) at (0,0) {}; + \node (exchange) [def,above=of origin,draw]{Exchange}; + \node (customer) [def, draw, below left=of origin] {Customer}; + \node (merchant) [def, draw, below right=of origin] {Merchant}; + \node (auditor) [def, draw, above right=of origin]{Auditor}; + + \tikzstyle{C} = [color=black, line width=1pt] + + \draw [<-, C] (customer) -- (exchange) node [midway, above, sloped] (TextNode) {withdraw coins}; + \draw [<-, C] (exchange) -- (merchant) node [midway, above, sloped] (TextNode) {deposit coins}; + \draw [<-, C] (merchant) -- (customer) node [midway, above, sloped] (TextNode) {spend coins}; + \draw [<-, C] (exchange) -- (auditor) node [midway, above, sloped] (TextNode) {verify}; + +\end{tikzpicture} +\caption{Taler system overview.} +\label{fig:system} +\end{figure} + +\section{Customer perspective} + +In Taler, customers use a {\em wallet} to withdraw, hold, and spend coins. +Withdrawing coins requires the customer to authenticate and to optionally +authorize the specific transaction, e.g. via a PIN/TAN method as commonly used +by banks. Afterwards, the customer can anonymously spend their coins by visiting +merchants without having to authenticate for each transaction. + +The wallet is implemented as a cross-platform browser extension. All +cryptographic operations and access to sensitive data are executed in a +component that is isolated from websites the user visits. + +By necessity, the wallet leaks one bit of information to websites that the user +visits, namely whether the wallet is installed and activated by the user. +Websites cannot access the customer's balance or purchase history. This +however also means that all cryptographic tokens of value are kept locally, and +the customer is responsible for not losing them. Future versions of the wallet +will provide encrypted backups and synchronization between the wallets of a +user. + +A common activity for online content is sharing and bookmarking. +Taler specifically provides support to make this easy for the user. +A resource that was purchased is identified by a unique \emph{fulfillment URL} +for each purchase of the resource. + + +\begin{figure*}[h!] +\begin{center} +\begin{tikzpicture}[ + font=\sffamily, + every matrix/.style={ampersand replacement=\&,column sep=2cm,row sep=2cm}, + source/.style={draw,thick,rounded corners,fill=green!20,inner sep=.3cm}, + process/.style={draw,thick,circle,fill=blue!20}, + sink/.style={source,fill=green!20}, + datastore/.style={draw,very thick,shape=datastore,inner sep=.3cm}, + dots/.style={gray,scale=2}, + to/.style={->,>=stealth',shorten >=1pt,semithick,font=\sffamily\footnotesize}, + every node/.style={align=center}] + + % Position the nodes using a matrix layout + \matrix{ + \node[source] (wallet) {Taler Wallet}; + \& \node[process] (browser) {Browser}; + \& \node[process] (shop) {Web shop}; + \& \node[sink] (backend) {Taler backend}; \\ + }; + + % Draw the arrows between the nodes and label them. + \draw[to] (browser) to[bend right=50] node[midway,above] {(4) signed contract} + node[midway,below] {(signal)} (wallet); + \draw[to] (wallet) to[bend right=50] node[midway,above] {(signal)} + node[midway,below] {(5) signed coins} (browser); + \draw[<->] (browser) -- node[midway,above] {(3,6) custom} + node[midway,below] {(HTTP(S))} (shop); + \draw[to] (shop) to[bend right=50] node[midway,above] {(HTTP(S))} + node[midway,below] {(1) proposed contract / (7) signed coins} (backend); + \draw[to] (backend) to[bend right=50] node[midway,above] {(2) signed contract / (8) confirmation} + node[midway,below] {(HTTP(S))} (shop); +\end{tikzpicture} +\end{center} + \caption{Both the customer's client and the merchant's server execute + sensitive cryptographic operations in a secured + background/backend that is protected against direct access. + Interactions between the Taler components + (Figure~\ref{fig:system}) are not shown. Existing system + security mechanisms are used to isolate the cryptographic + components (boxes) from the complex rendering logic + of existing Web applications (circles).} + \label{fig:frobearch} +\end{figure*} + +% maybe mention division into two phases (a) contract offer/accept +% and (b) contract execution/replay + +% How far does this allow the merchant +Should the session state that allows the user to access the content be lost, +visiting the fulfillment URL will transparently restore the session state by +transparently replaying the payment with the same digital value tokens from the +user's wallet. Replaying a contract is only allowed from the domain that the +contract originated from, and thus does not allow arbitrary websites to obtain +information about previous purchases that the customer made. Sharing the +fulfillment URL with a user that did not pay for the associated digital +contract will result in the expected behavior, namely that they receiving a new +instance of the digital contract with the opportunity to pay for it. + +% idea while writing this: why do we need a correlation id +% if we already have the url? i.e. the non-fulfillment URL +% that just identifies the resource ... + +The case where a user already payed for a resource and then visits +the resource URL (instead of the fulfillment URL) after losing temporary +session state is also handled as expected, since the wallet component will +look for contracts that refer to the same resource. + +While Taler is designed to work well with digital resources on the web, +it can also be used for more traditional purchases. The resource that +is being payed for then represents the shopping cart of items that +are being purchased. + +%\newpage +\section{Merchant perspective} + + + +%\begin{figure}[b!] +%\includegraphics[width=0.45\textwidth]{figs/taler-pay.pdf} +%\caption{Payment processing with Taler.} +%\label{fig:taler-pay} +%\end{figure} + + +A new payment system must also be easy to integrate and deploy for merchants. +Figure~\ref{fig:frobearch} shows how the security critical payment components of +Taler interact with the logic of existing Web shops. First, the Web shop +front-end is responsible for constructing the shopping cart. For this, +the shop front-end generates the usual Web pages which are shown to the +user's browser client front-end. Once the order has been constructed, +the shop front-end gives a {\em proposed contract} in JSON format to +the payment backend, which signs it and returns it to the front-end. +The front-end then transfers the signed contract over the network, and +passes it to the wallet. Here, the wallet operates from a secure +background context on the client side, which allows the user to securely +accept the payment, and to perform the cryptographic operations in a +context that is protected from the Web shop. If the user accepts, the +resulting signed coins are transferred from the client to the server, +again by a protocol that the merchant can customize to fit the +existing infrastructure. + + + +Instead of adding any cryptographic logic to the merchant front-end, +the generic Taler merchant backend allows the implementor to delegate +handling of the coins to the payment backend, which validates the +coins, deposits them at the exchange, and finally validates and +persists the receipt from the exchange. The merchant backend then +communicates the result of the transaction to the front\-end, which is +then responsible for executing the business logic to fulfill the +order. +As a result of this setup, the cryptographic details of the +Taler protocol do not have to be re-implemented by each merchant. +Instead, existing Web shops implemented in a multitude of programming +languages can rather trivially add support for Taler by {\bf (1)} upon +request, generating a contract in JSON based on the shopping cart, +{\bf (2)} allowing the backend to sign the contract before sending it +to the client, {\bf (7)} passing coins received in payment for a +contract to the backend and {\bf (8)} executing fulfillment business +logic if the backend confirms the validity of the payment. + + +To setup a Taler backend, the merchant only needs to configure it with the +respective wire transfer routing details, such as an IBAN number. The +customer's authentication of the Web shop continues to rely upon +\mbox{HTTPS}/X.509. + +\section{Conclusion} + +We encourage everyone to try our prototype for Taler +at \url{https://demo.taler.net/}. + +% These APIs are all RESTful in the modern sense because that greatly +% simplify integrating Taler with web shops and browsers. + +\section*{Acknowledgements} + +This work benefits from the financial support of the Brittany Region +(ARED 9178) and a grant from the Renewable Freedom Foundation. + + +\bibliographystyle{abbrv} +\bibliography{ui,btc,taler,rfc} + +\end{document} diff --git a/test/run_tests.js b/test/run_tests.js index 88aded741..0c7b2c4c1 100644 --- a/test/run_tests.js +++ b/test/run_tests.js @@ -24,6 +24,9 @@ let emsc = require("../lib/emscripten/libwrapper.js"); let System = require("systemjs"); +// When instrumenting code with istanbul, +// automatic module type detection fails, +// thus we specify it here manually. System.config({ defaultJSExtensions: true, meta: { |