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| -rw-r--r-- | README.mediawiki | 50 | ||||
| -rw-r--r-- | bip-0017.mediawiki | 4 | ||||
| -rw-r--r-- | bip-0021.mediawiki | 9 | ||||
| -rw-r--r-- | bip-0047.mediawiki | 252 | ||||
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| -rw-r--r-- | bip-0070/paymentrequest.proto | 2 | ||||
| -rw-r--r-- | bip-0101.mediawiki | 2 | ||||
| -rw-r--r-- | bip-0105.mediawiki | 106 | ||||
| -rw-r--r-- | bip-0106.mediawiki | 80 | ||||
| -rw-r--r-- | bip-0111.mediawiki | 85 | ||||
| -rw-r--r-- | bip-0112.mediawiki | 246 | ||||
| -rw-r--r-- | bip-0113.mediawiki | 137 | ||||
| -rw-r--r-- | bip-0120.mediawiki | 152 | ||||
| -rw-r--r-- | bip-0121.mediawiki | 146 |
22 files changed, 1270 insertions, 9 deletions
diff --git a/README.mediawiki b/README.mediawiki index 13e38e8..089d9b5 100644 --- a/README.mediawiki +++ b/README.mediawiki @@ -64,8 +64,8 @@ Those proposing changes should consider that ultimately consent may rest with th | [[bip-0017.mediawiki|17]] | OP_CHECKHASHVERIFY (CHV) | Luke Dashjr +| Standard | Withdrawn -| Draft |- | [[bip-0018.mediawiki|18]] | hashScriptCheck @@ -199,6 +199,12 @@ Those proposing changes should consider that ultimately consent may rest with th | Standard | Draft |- +| [[bip-0047.mediawiki|47]] +| Reusable Payment Codes for Hierarchical Deterministic Wallets +| Justus Ranvier +| Informational +| Draft +|- | [[bip-0050.mediawiki|50]] | March 2013 Chain Fork Post-Mortem | Gavin Andresen @@ -295,6 +301,48 @@ Those proposing changes should consider that ultimately consent may rest with th | Gavin Andresen | Standard | Draft +|- +| [[bip-0105.mediawiki|105]] +| Consensus based block size retargeting algorithm +| BtcDrak +| Standard +| Draft +|- +| [[bip-0106.mediawiki|106]] +| Dynamically Controlled Bitcoin Block Size Max Cap +| Upal Chakraborty +| Standard +| Draft +|- +| [[bip-0111.mediawiki|111]] +| NODE_BLOOM service bit +| Matt Corallo and Peter Todd +| Standard +| Draft +|- +| [[bip-0112.mediawiki|112]] +| CHECKSEQUENCEVERIFY +| BtcDrak and Mark Friedenbach +| Standard +| Draft +|- +| [[bip-0113.mediawiki|113]] +| Median time-past as endpoint for lock-time calculations +| Thomas Kerin and Mark Friedenbach +| Standard +| Draft +|- +| [[bip-0120.mediawiki|120]] +| Proof of Payment +| Kalle Rosenbaum +| Standard +| Draft +|- +| [[bip-0121.mediawiki|121]] +| Proof of Payment URI scheme +| Kalle Rosenbaum +| Standard +| Draft |} <!-- IMPORTANT! See the instructions at the top of this page, do NOT JUST add BIPs here! --> diff --git a/bip-0017.mediawiki b/bip-0017.mediawiki index 07dca96..44011d5 100644 --- a/bip-0017.mediawiki +++ b/bip-0017.mediawiki @@ -2,8 +2,8 @@ BIP: 17 Title: OP_CHECKHASHVERIFY (CHV) Author: Luke Dashjr <luke+bip17@dashjr.org> - Status: Draft - Type: Withdrawn + Status: Withdrawn + Type: Standards Track Created: 2012-01-18 </pre> diff --git a/bip-0021.mediawiki b/bip-0021.mediawiki index 00d9a53..2706926 100644 --- a/bip-0021.mediawiki +++ b/bip-0021.mediawiki @@ -56,6 +56,7 @@ The scheme component ("bitcoin:") is case-insensitive, and implementations must *address: bitcoin address *message: message that describes the transaction to the user ([[#Examples|see examples below]]) *size: amount of base bitcoin units ([[#Transfer amount/size|see below]]) +*paycode: payment code (BIP-47) *(others): optional, for future extensions ==== Transfer amount/size ==== @@ -67,6 +68,11 @@ I.e. amount=50.00 or amount=50 is treated as 50 BTC, and amount=50,000.00 is inv Bitcoin clients MAY display the amount in any format that is not intended to deceive the user. They SHOULD choose a format that is foremost least confusing, and only after that most reasonable given the amount requested. For example, so long as the majority of users work in BTC units, values should always be displayed in BTC by default, even if mBTC or TBC would otherwise be a more logical interpretation of the amount. + +==== Payment code ==== + +If a URI provides a payment code, and if the client supports BIP-47, then the resulting transaction SHOULD construct a transaction per BIP-47 instead of using the address provided in the URI. + == Rationale == ===Payment identifiers, not person identifiers=== @@ -122,3 +128,6 @@ Characters must be URI encoded properly. === Bitcoin clients === * Bitcoin-Qt supports the old version of Bitcoin URIs (ie without the req- prefix), with Windows and KDE integration as of commit 70f55355e29c8e45b607e782c5d76609d23cc858. +==References== + +* [[bip-0047.mediawiki|BIP47 - Reusable Payment Codes for Hierarchical Deterministic Wallets]] diff --git a/bip-0047.mediawiki b/bip-0047.mediawiki new file mode 100644 index 0000000..15c5a8b --- /dev/null +++ b/bip-0047.mediawiki @@ -0,0 +1,252 @@ +RECENT CHANGES: + +* (18 Sep 2015) Clarify decoding of notification transactions + +<pre> + BIP: 47 + Title: Reusable Payment Codes for Hierarchical Deterministic Wallets + Authors: Justus Ranvier <justus@openbitcoinprivacyproject.org> + Status: Draft + Type: Informational + Created: 2015-04-24 +</pre> + +==Abstract== + +This BIP defines a technique for creating a payment code which can be publicly advertised and associated with a real-life identity without creating the loss of security or privacy inherent to P2PKH address reuse. + +This BIP is a particular application of BIP43 and is intended to supplement HD wallets which implement BIP44. + +The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. + +==Motivation== + +Payment codes add identity information to transactions which is useful in a merchant-customer interaction while protecting the privacy of users. Payment codes provide the privacy benefits of Darkwallet-style Stealth Addresses to SPV clients without requiring the assistance of a trusted full node and while greatly reducing reliance on blockchain storage. + +==Path levels== + +We define the following 3 levels in BIP32 path: + +<pre> +m / purpose' / coin_type' / identity' +</pre> + +Apostrophe in the path indicates that BIP32 hardened derivation is used. + +Each level has a special meaning, described in the chapters below. + +===Purpose=== + +Purpose is a constant set to 47' (or 0x8000002F) following the BIP43 recommendation. It indicates that the subtree of this node is used according to this specification. + +===Coin type=== + +The coin type field is identical to the same field in BIP44 + +Hardened derivation is used at this level. + +===Identity=== + +Identity is a particular extended public/private key pair. The extended public key is a payment code. + +Identities SHOULD have 1:1 correspondence with a BIP44 account, as in each BIP44 account in an HD wallet should be assigned exactly one payment code which shares the same index value. + +Hardened derivation is used at this level. + +Except where noted, all keys derived from a payment code use the public derivation method. + +====Binary Serialization==== + +A payment code contains the following elements: + +* Byte 0: type. required value: 0x01 +* Byte 1: features bit field. All bits must be zero except where specified elsewhere in this specification +** Bit 0: Bitmessage notification +** Bits 1-7: reserved +* Byte 2: sign. required value: 0x02 or 0x03 +* Bytes 3 - 34: x value, must be a member of the secp256k1 group +* Bytes 35 - 66: chain code +* Bytes 67 - 79: reserved for future expansion, zero-filled unless otherwise noted + +====Base58 Serialization==== + +When a payment code is presented to the user, it SHOULD be presented encoded in Base58Check form. + +* The version byte is: 0x23 (produces a "P" as the first character of the serialized form) +* The payload is the binary serialization of the payment code + +===Protocol=== + +In the following examples, Alice and Bob are identities with a corresponding payment codes. Alice initiates a Bitcoin transaction, and Bob is the recipient of the transaction. + +It is assumed that Alice can easily obtain Bob's payment code via a suitable method outside the scope of the payment code protocol. + +====Definitions==== + +* Payment code: an extended public key which is associated with a particular identity +* Notification address: the P2PKH address associated with the 0<sup>th</sup> public key derived from a payment code +* Notification transaction: a transaction which sends an output to a notification address which includes an embedded payment code + +====Notification Transaction==== + +Prior to the first time Alice initiates a transaction to Bob, Alice MUST inform Bob of her payment code via the following procedure: + +# Alice constructs a transaction which sends a small quantity of bitcoins to Bob's notification address (notification transaction) +## The inputs selected for this transaction MUST NOT be easily associated with Alice's notification address +# Alice derives a unique shared secret using ECDH: +## Alice selects the private key corresponding to the first exposed public key, of the first pubkey-exposing input, of the transaction: <pre>a</pre> +## Alice selects the public key associated with Bob's notification address: <pre>B, where B = bG</pre> +## Alice calculates a secret point: <pre>S = aB</pre> +## Alice expresses the secret point in compressed DER format, then calculates a scalar shared secret: <pre>s = SHA256(S)</pre> +# Alice serializes her payment code in binary form. +# Alice renders her payment code (P) unreadable to anyone except Bob by: +## Replace the x value with x': <pre>x' = s XOR (x value)</pre> +## Replace the chain code with c': <pre>c' = sha256(s) XOR (chain code)</pre> +# Alice adds an OP_RETURN output to her transaction which consists of P. +<img src="bip-0047/reusable_payment_codes-01.png" /> + +# Bob watches for any transactions which create an output at his notification address. +# When a transaction is received, the client examines it to determine if it contains a standard OP_RETURN output with an 80 byte payload (notification transactions). +# If the first byte of the payload in a notification transaction is 0x01: +## Bob selects the first exposed public key, of the first pubkey-exposing input, of the transaction: <pre>A, where A = aG</pre> +## Bob selects the private key associated with his notification address: <pre>b</pre> +## Bob calculates a secret point: <pre>S = bA</pre> +## Bob expresses the secret point in compressed DER format, then calculates a scalar shared secret: <pre>s = SHA256(S)</pre> +## Bob interprets the 80 byte payload as a payment code, except: +### Replace the x value with x': <pre>x' = s XOR (x value)</pre> +### Replace the chain code with c': <pre>c' = sha256(s) XOR (chain code)</pre> +## If the updated x value is a member of the secp256k1 group, the payment code is valid. +## If the updated x value is not a member of the secp256k1 group, the payment code is ignored. + +Now that Bob's client has received Alice's payment code, it is possible for Alice to send payments (up to 2<sup>32</sup> payments) to Bob. + +Alice will never again need to send a notification transaction to Bob. + +Bitcoins received via notification transactions require special handling in order to avoid privacy leaks: + +# The value of outputs received to notification addresses MUST NOT be displayed to the user as part of their spendable balance. +# Outputs received to notification addresses MUST NOT be used as inputs for any transaction that involve ECDH calculations using any of the user's payment codes. +# Outputs received to notification addresses MAY be passed through a mixing service before being added to the user's spendable balance. +# Outputs received to notification addresses MAY be donated to miners using dust-b-gone or an equivalent procedure. + +====Sending==== + +# Each time Alice wants to initiate a transaction to Bob, Alice derives a unique P2PKH address for the transaction using ECDH follows: +## Alice selects the 0th private key derived from her payment code: <pre>a</pre> +## Alice selects the next unused public key derived from Bob's payment code, starting from zero: <pre>B, where B = bG</pre> +### The "next unused" public key is based on an index specific to the Alice-Bob context, not global to either Alice or Bob +## Alice calculates a secret point: <pre>S = aB</pre> +## Alice expresses the secret point in compressed DER format, then calculates a scalar shared secret: <pre>s = SHA256(S)</pre> +### If the value of s is not in the secp256k1 group, Alice MUST increment the index used to derive Bob's public key and try again. +## Alice uses the scalar shared secret to calculate the ephemeral public key used to generate the P2PKH address for this transaction: <pre>B' = B + sG</pre> +<img src="bip-0047/reusable_payment_codes-04.png" /> +<img src="bip-0047/reusable_payment_codes-05.png" /> +# Bob is watching for incoming payments on B' ever since he received the notification transaction from Alice. +## Bob calculates n shared secrets with Alice, using the 0<sup>th</sup> public key derived Alice's payment code, and private keys 0 - n derived from Bob's payment code, where n is his desired lookahead window. +## Bob calculates the ephemeral deposit addresses using the same procedure as Alice: <pre>B' = B + sG</pre> +## Bob calculate the private key for each ephemeral address as: <pre>b' = b + s</pre> +<img src="bip-0047/reusable_payment_codes-02.png" /> +<img src="bip-0047/reusable_payment_codes-03.png" /> + +====Refunds==== + +Because Bob learns Alice's payment code as part of the process of receiving a payment, Bob has all the information he needs in order to send a refund to Alice. + +A refund transaction is identical to a payment transactions, with only the roles of the participants switches. + +Bob MUST send a notification transaction to Alice prior to the first time he sends funds to Alice, even if he has received transactions from her in the past. + +<img src="bip-0047/reusable_payment_codes-06.png" /> + +====Anonymous Payments==== + +If Alice does not want her payment to Bob to be associated with her identity, she generates an ephemeral payment code to use for the transaction. + +* Ephemeral payment codes are the hardened children of a payment code, starting from an index of zero. +* An ephemeral payment code SHOULD only be used for a single outgoing payment. +* The notification address of an ephemeral payment code MUST be monitored for notification transactions in order to detect incoming refund payments +* The correspondence between BIP44 accounts and ephemeral payment codes is 1:many + +====Cold Storage==== + +* Unlike traditional watching-only wallets, those associated with payment codes help in cold storage can not detect incoming payments immediately. +* When the watching-only wallet detects an incoming notification transaction, it packages the transaction in an implementation-specific format suitable for transfer to the offline device. +* The offline device recovers the payment code, then pre-generates a large number of relevant keypairs (example: 10000) in order to minimize the need for air gap round trips. +* The offline device then packages the relevant public keys in an implementation-specific format suitable for transfer to the online device. +* The online device can then watch for incoming payments using a suitable lookahead window. +* If the lookahead window reaches the end of the pre-generated public keys, the user must generate more keys on the offline device and transfer them to the online device. + +====Wallet Recovery==== + +Normal operation of a payment code-enabled wallet can be performed by an SPV client and does not require access to a complete copy of the blockchain. + +Recovering a wallet from a seed, however, does require access to a fully-indexed blockchain. + +The required data may be obtained from copy of the blockchain under the control of the user, or via a publicly-queriable blockchain explorer. + +When querying a public blockchain explorer, wallets SHOULD connect to the explorer through Tor (or equivalent) and SHOULD avoid grouping queries in a manner that associates ephemeral addresses with each other. + +Previously-spendable funds will generally not be lost or become inaccessible after a recovery from a seed, but all information regarding previous outgoing payments will be lost. + +The metadata which a wallet must store regarding the state an identity consists of: + +# A list of every payment code to which the identity has sent a notification transaction. +## This list is lost if a wallet must be recovered from a seed. +## The recovered wallet MUST send notification transactions as if it was a newly-created wallet +# The index value corresponding to the next unused pubkey for each payment code on the previous list +## This value can be recovered by checking each ephemeral deposit address in sequence for transactions. +## Wallets MAY use a lookahead window capable of detecting gaps in the address sequence during this recovery operation. +# The index value of the next unused ephemeral payment code. +## Recovering all incoming funds associated with ephemeral payment codes with 100% certainty requires exhausting the entire 2<sup>32</sup> address space of potential ephemeral payment codes. +### In most cases, less than 100% certainty is acceptable as long as a fallback "deep scan" is available as an option to the user. +## The wallet checks the notification address for each ephemeral payment code for notification transactions in order to recover associated funds. +## Since most ephemeral payment codes will not receive a refund transaction wallets SHOULD use a large lookahead window for this recovery operation. +## The recovered value MUST be chosen as a number higher than any ephemeral payment code which has received a notification transaction. + +===Wallet Sharing=== + +Wallets using payment codes generally should not be shared across multiple devices, given the need to synchronize metadata between each instance. + +If wallets are shared between devices without a synchronization mechanism, undesirable address reuse can occur. + +Wallets may perform an OPTIONAL check for existing transactions to an ephemeral deposit addresses prior to sending a transaction by checking a local copy of the blockchain or querying a public blockchain explorer via Tor or equivalent. + +===Alternate Notification Methods=== + +In order to ensure that no funds will be lost in the event the recipient must recover their wallet from a seed, the sender MUST send a notification transaction the first time the sender interacts with a particular recipient. + +A recipient MAY choose to designate alternate notification methods which the sender may use in addition to a notification transaction. + +If the recipient specifies an alternate notification method, a compliant implementation MAY refrain from continually monitoring the notification address and SHOULD check the notification address periodically to detect payments sent by users who can not employ the alternate method. + +A recipient specifies their preference for alternate notification by setting the appropriate bits in the feature byte of their payment code. + +===Bitmessage Notification=== + +A recipient prefers to receive notifications via Bitmessage indiates this preference by: + +* Setting bit 0 of the features byte to 1 +* Setting byte 67 of the serialized payment code to the desired Bitmessage address version +* Setting byte 67 of the serialized payment code to the desired Bitmessage stream number + +The sender uses this information to construct a valid notification Bitmessage address: + +# Derive a Bitmessage signing key as: <pre>B = payment code / 0 / 0</pre> +# Initialize a counter at 1: <pre>n</pre> +# Derive a candidate encryption key as: <pre>B' = payment code / 0 / n</pre> +# If the combination of B and B` do not form a valid Bitmessage address, increment n by one and try again +# Use the address version, signing key, encryption key, and stream number to construct a Bitmessage address per the Bitmessage protocol + +The sender transmits their payment code in base58 form to the calculated Bitmessage address. + +In order to use Bitmessage notification, the recipient must have a Bitmessage client which listens at the address which the senders will derive and is capable of relaying received payment codes to the Bitcoin wallet. + +==Reference== + +* [[bip-0032.mediawiki|BIP32 - Hierarchical Deterministic Wallets]] +* [[bip-0043.mediawiki|BIP43 - Purpose Field for Deterministic Wallets]] +* [[bip-0044.mediawiki|BIP44 - Multi-Account Hierarchy for Deterministic Wallets]] +* [[https://github.com/petertodd/dust-b-gone|dust-b-gone]] +* [[https://en.bitcoin.it/wiki/Base58Check_encoding|Base58Check encoding]] +* [[https://bitmessage.org/bitmessage.pdf|Bitmessage]] +* [[https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-April/007812.html|Mailing list discussion]] diff --git a/bip-0047/reusable_payment_codes-01.png b/bip-0047/reusable_payment_codes-01.png Binary files differnew file mode 100644 index 0000000..30a003f --- /dev/null +++ b/bip-0047/reusable_payment_codes-01.png diff --git a/bip-0047/reusable_payment_codes-02.png b/bip-0047/reusable_payment_codes-02.png Binary files differnew file mode 100644 index 0000000..da81d63 --- /dev/null +++ b/bip-0047/reusable_payment_codes-02.png diff --git a/bip-0047/reusable_payment_codes-03.png b/bip-0047/reusable_payment_codes-03.png Binary files differnew file mode 100644 index 0000000..3087293 --- /dev/null +++ b/bip-0047/reusable_payment_codes-03.png diff --git a/bip-0047/reusable_payment_codes-04.png b/bip-0047/reusable_payment_codes-04.png Binary files differnew file mode 100644 index 0000000..9738ca2 --- /dev/null +++ b/bip-0047/reusable_payment_codes-04.png diff --git a/bip-0047/reusable_payment_codes-05.png b/bip-0047/reusable_payment_codes-05.png Binary files differnew file mode 100644 index 0000000..5e93559 --- /dev/null +++ b/bip-0047/reusable_payment_codes-05.png diff --git a/bip-0047/reusable_payment_codes-06.png b/bip-0047/reusable_payment_codes-06.png Binary files differnew file mode 100644 index 0000000..c5619da --- /dev/null +++ b/bip-0047/reusable_payment_codes-06.png diff --git a/bip-0062.mediawiki b/bip-0062.mediawiki index 7bd88a6..feb4d58 100644 --- a/bip-0062.mediawiki +++ b/bip-0062.mediawiki @@ -38,7 +38,7 @@ The first six and part of the seventh can be fixed by extra consensus rules, but ===New rules=== Seven extra rules are introduced, to combat exactly the seven first sources of malleability listed above: -# '''Canonically encoded ECDSA signatures''' An ECDSA signature passed to OP_CHECKSIG, OP_CHECKSIGVERIFY, OP_CHECKMULTISIG or OP_CHECKMULTISIGVERIFY must be encoded using strict DER encoding. To provide a compact way to deliberately create an invalid signature for with OP_CHECKSIG and OP_CHECKMULTISIG the empty byte array (the result of OP_0) is also allowed. Doing a verification with a non-DER signature makes the entire script evaluate to False (not just the signature verification). See reference: [[#der-encoding|DER encoding]]. +# '''Canonically encoded ECDSA signatures''' An ECDSA signature passed to OP_CHECKSIG, OP_CHECKSIGVERIFY, OP_CHECKMULTISIG or OP_CHECKMULTISIGVERIFY must be encoded using strict DER encoding. To provide a compact way to deliberately create an invalid signature for OP_CHECKSIG and OP_CHECKMULTISIG, an empty byte array (i.e., the result of OP_0) is also allowed. Doing a verification with a non-DER signature makes the entire script evaluate to False (not just the signature verification). See reference: [[#der-encoding|DER encoding]]. # '''Non-push operations in scriptSig''' Only data pushes are allowed in scriptSig. Evaluating any other operation makes the script evaluate to false. See reference: [[#push-operators|Push operators]]. # '''Push operations in scriptSig of non-standard size type''' The smallest possible push operation must be used when possible. Pushing data using an operation that could be encoded in a shorter way makes the script evaluate to false. See reference: [[#push-operators|Push operators]]. # '''Zero-padded number pushes''' Any time a script opcode consumes a stack value that is interpreted as a number, it must be encoded in its shortest possible form. 'Negative zero' is not allowed. See reference: [[#numbers|Numbers]]. diff --git a/bip-0066.mediawiki b/bip-0066.mediawiki index 41cbd8f..1235afd 100644 --- a/bip-0066.mediawiki +++ b/bip-0066.mediawiki @@ -2,7 +2,7 @@ BIP: 66 Title: Strict DER signatures Author: Pieter Wuille <pieter.wuille@gmail.com> - Status: Draft + Status: Final Type: Standards Track Created: 2015-01-10 </pre> diff --git a/bip-0067.mediawiki b/bip-0067.mediawiki index 9c4f3de..8be5c9b 100644 --- a/bip-0067.mediawiki +++ b/bip-0067.mediawiki @@ -4,8 +4,8 @@ Title: Deterministic Pay-to-script-hash multi-signature addresses through public key sorting Author: Thomas Kerin, Jean-Pierre Rupp, Ruben de Vries Status: Draft - Type: Standard - Created: 8 February 2015 + Type: Standards Track + Created: 2015-02-08 </pre> ==Abstract== diff --git a/bip-0070/paymentrequest.proto b/bip-0070/paymentrequest.proto index 6680810..717946e 100644 --- a/bip-0070/paymentrequest.proto +++ b/bip-0070/paymentrequest.proto @@ -3,7 +3,7 @@ // // Use fields 1000+ for extensions; // to avoid conflicts, register extensions via pull-req at -// https://github.com/bitcoin/bips/bip-0070/extensions.mediawiki +// https://github.com/bitcoin/bips/blob/master/bip-0070/extensions.mediawiki // package payments; diff --git a/bip-0101.mediawiki b/bip-0101.mediawiki index 9a78255..a76db0f 100644 --- a/bip-0101.mediawiki +++ b/bip-0101.mediawiki @@ -44,7 +44,7 @@ Expressed in pseudo-code, using integer math, assuming that block_timestamp is a Deployment shall be controlled by hash-power supermajority vote (similar to the technique used in BIP34), but the earliest possible activation time is 2016-01-11 00:00:00 UTC. -Activation is achieved when 750 of 1,000 consecutive blocks in the best chain have a version number with bits 1,2,3 and 14 set (0x20000007 in hex). The activation time will be the timestamp of the 750'th block plus a two week (1,209,600 second) grace period to give any remaining miners or services time to upgrade to support larger blocks. If a supermajority is achieved more than two weeks before 2016-01-11 00:00:00 UTC, the activation time will be 2016-01-11 00:00:00 UTC. +Activation is achieved when 750 of 1,000 consecutive blocks in the best chain have a version number with the first, second, third, and thirtieth bits set (0x20000007 in hex). The activation time will be the timestamp of the 750'th block plus a two week (1,209,600 second) grace period to give any remaining miners or services time to upgrade to support larger blocks. If a supermajority is achieved more than two weeks before 2016-01-11 00:00:00 UTC, the activation time will be 2016-01-11 00:00:00 UTC. Block version numbers are used only for activation; once activation is achieved, the maximum block size shall be as described in the specification section, regardless of the version number of the block. diff --git a/bip-0105.mediawiki b/bip-0105.mediawiki new file mode 100644 index 0000000..cbd309d --- /dev/null +++ b/bip-0105.mediawiki @@ -0,0 +1,106 @@ +<pre> + BIP: 105 + Title: Consensus based block size retargeting algorithm + Author: BtcDrak <btcdrak@gmail.com> + Status: Draft + Type: Standards Track + Created: 2015-08-21 +</pre> + +==Abstract== + +A method of altering the maximum allowed block size of the Bitcoin protocol +using a consensus based approach. + +==Motivation== + +There is a belief that Bitcoin cannot easily respond to raising the +blocksize limit if popularity was to suddenly increase due to a mass adoption +curve, because co-ordinating a hard fork takes considerable time, and being +unable to respond in a timely manner would irreparably harm the credibility of +bitcoin. + +Additionally, predetermined block size increases are problematic because they +attempt to predict the future, and if too large could have unintended +consequences like damaging the possibility for a fee market to develop +as block subsidy decreases substantially over the next 9 years; introducing +or exacerbating mining attack vectors; or somehow affect the network in unknown +or unpredicted ways. Since fixed changes are hard to deploy, the damage could be +extensive. + +Dynamic block size adjustments also suffer from the potential to be gamed by the +larger hash power. + +Free voting as suggested by BIP100 allows miners to sell their votes out of band +at no risk, and enable the sponsor the ability to manipulate the blocksize. +It also provides a cost free method or the larger pools to vote in ways to +manipulate the blocksize such to disadvantage or attack smaller pools. + + +==Rationale== + +By introducing a cost to increase the block size ensures the mining community +will collude to increase it only when there is a clear necessity, and reduce it +when it is unnecessary. Larger miners cannot force their wishes so easily +because not only will they have to pay extra a difficulty target, then can be +downvoted at no cost by the objecting hash power. + +Using difficulty as a penalty is better than a fixed cost in bitcoins because it +is less predictable. + +In order to prevent miners having complete control over blocksize, an upper +limit is required at protocol level. This feature ensures full nodes retain +control over consensus, remembering full nodes are the mechanism to keep miners +honest. + + +==Specification== + +The initial block size limit shall be 1MB. + +Each time a miner creates a block, they may vote to increase or decrease the +blocksize by a maximum of 10% of the current block size limit. These votes will +be used to recalculate the new block size limit every 2016 blocks. + +Votes are cast using the block's coinbase transaction scriptSig. + +As per BIP34, the coinbase transaction scriptSig starts with a push of the block +height. The next push is a little-endian number representing the preferred block +size in bytes. For example, 0x4c(OP_PUSHDATA1) 0x03(size of constant) 0x80 0x84 0x1e(2MB) +or 0x4c(OP_PUSHDATA1) 0x04(size of constant) 0x80 0x96 0x98 0x00(10MB). + +If a miner votes for an increase, the block hash must meet a difficulty target +which is proportionally larger than the standard difficulty target based on the +percentage increase they voted for. + +Votes proposing decreasing the block size limit do not need to meet a higher +difficulty target. + +Miners can vote for no change by voting for the current block size. + +For blocks to be valid the blockhash must meet the required difficulty target +for the vote otherwise the block is invalid and will be rejected. + +Every 2016 blocks, the block size limit will be recalculated by the median of +all votes in the last 2016 blocks. This will redefine the block size limit for +the next 2016 blocks. + +Blocks that are larger than the calculated base block size limit are invalid and +will be rejected. + +The base block size limit may not reduce below 1MB or increase above 8MB. + + +==Acknowledgements== + +This proposal is based on ideas and concepts derived from the writings of +Meni Rosenfeld and Gregory Maxwell. + + +==References== + +[[bip-0034.mediawiki|BIP34]] + +==Copyright== + +This work is placed in the public domain. diff --git a/bip-0106.mediawiki b/bip-0106.mediawiki new file mode 100644 index 0000000..e9018fa --- /dev/null +++ b/bip-0106.mediawiki @@ -0,0 +1,80 @@ +<pre> + BIP: 106 + Title: Dynamically Controlled Bitcoin Block Size Max Cap + Author: Upal Chakraborty <bitcoin@upalc.com> + Status: Draft + Type: Standards Track + Created: 2015-08-24 +</pre> + +==Abstract== + +This BIP proposes replacing the fixed one megabyte maximum block size with a dynamically controlled maximum block size that may increase or decrease with difficulty change depending on various network factors. I have two proposals regarding this... + +i. Depending only on previous block size calculation. + +ii. Depending on previous block size calculation and previous Tx fee collected by miners. + +==Motivation== + +With increased adoption, transaction volume on bitcoin network is bound to grow. If the one megabyte max cap is not changed to a flexible one which changes itself with changing network demand, then adoption will hamper and bitcoin's growth may choke up. Following graph shows the change in average block size since inception... + +https://blockchain.info/charts/avg-block-size?timespan=all&showDataPoints=false&daysAverageString=1&show_header=true&scale=0&address= + +==Specification== + +===Proposal 1 : Depending only on previous block size calculation=== + + If more than 50% of block's size, found in the first 2000 of the last difficulty period, is more than 90% MaxBlockSize + Double MaxBlockSize + Else if more than 90% of block's size, found in the first 2000 of the last difficulty period, is less than 50% MaxBlockSize + Half MaxBlockSize + Else + Keep the same MaxBlockSize + +===Proposal 2 : Depending on previous block size calculation and previous Tx fee collected by miners=== + + TotalBlockSizeInLastButOneDifficulty = Sum of all Block size of first 2008 blocks in last 2 difficulty period + TotalBlockSizeInLastDifficulty = Sum of all Block size of second 2008 blocks in last 2 difficulty period (This actually includes 8 blocks from last but one difficulty) + + TotalTxFeeInLastButOneDifficulty = Sum of all Tx fees of first 2008 blocks in last 2 difficulty period + TotalTxFeeInLastDifficulty = Sum of all Tx fees of second 2008 blocks in last 2 difficulty period (This actually includes 8 blocks from last but one difficulty) + + If ( ( (Sum of first 4016 block size in last 2 difficulty period)/4016 > 50% MaxBlockSize) AND (TotalTxFeeInLastDifficulty > TotalTxFeeInLastButOneDifficulty) AND (TotalBlockSizeInLastDifficulty > TotalBlockSizeInLastButOneDifficulty) ) + MaxBlockSize = TotalBlockSizeInLastDifficulty * MaxBlockSize / TotalBlockSizeInLastButOneDifficulty + Else If ( ( (Sum of first 4016 block size in last 2 difficulty period)/4016 < 50% MaxBlockSize) AND (TotalTxFeeInLastDifficulty < TotalTxFeeInLastButOneDifficulty) AND (TotalBlockSizeInLastDifficulty < TotalBlockSizeInLastButOneDifficulty) ) + MaxBlockSize = TotalBlockSizeInLastDifficulty * MaxBlockSize / TotalBlockSizeInLastButOneDifficulty + Else + Keep the same MaxBlockSize + +==Rationale== + +These two proposals have been derived after discussion on [https://bitcointalk.org/index.php?topic=1154536.0 BitcoinTalk] and [http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010285.html bitcoin-dev mailing list]. The original idea and its evolution in the light of various arguements can be found [http://upalc.com/maxblocksize.php here]. + +===Proposal 1 : Depending only on previous block size calculation=== + +This solution is derived directly from the indication of the problem. If transaction volume increases, then we will naturally see bigger blocks. On the contrary, if there are not enough transaction volume, but maximum block size is high, then only few blocks may sweep the mempool. Hence, if block size is itself taken into consideration, then maximum block size can most rationally be derived. Moreover, this solution not only increases, but also decreases the maximum block size, just like difficulty. + +===Proposal 2 : Depending on previous block size calculation and previous Tx fee collected by miners=== + +This solution takes care of stable mining subsidy. It will not increase maximum block size, if Tx fee collection is not increasing and thereby creating a Tx fee pressure on the market. On the other hand, though the block size max cap is dynamically controlled, it is very difficult to game by any party because the increase or decrease of block size max cap will take place in the same ratio of average block size increase or decrease. + +==Compatibility== + +This is a hard-forking change to the Bitcoin protocol; anybody running code that fully validates blocks must upgrade before the activation time or they will risk rejecting a chain containing larger-than-one-megabyte blocks. + +==Other solutions considered== + +[http://gtf.org/garzik/bitcoin/BIP100-blocksizechangeproposal.pdf Making Decentralized Economic Policy] - by Jeff Garzik + +[https://bitcointalk.org/index.php?topic=1078521.0 Elastic block cap with rollover penalties] - by Meni Rosenfeld + +[https://github.com/bitcoin/bips/blob/master/bip-0101.mediawiki Increase maximum block size] - by Gavin Andresen + +[https://gist.github.com/sipa/c65665fc360ca7a176a6 Block size following technological growth] - by Pieter Wuille + +[https://lightning.network/lightning-network-paper.pdf The Bitcoin Lightning Network: Scalable Off-Chain Instant Payments] - by Joseph Poon & Thaddeus Dryja + +==Deployment== + +If consensus is achieved, deployment can be made at a future block number at which difficulty will change. diff --git a/bip-0111.mediawiki b/bip-0111.mediawiki new file mode 100644 index 0000000..d3bd630 --- /dev/null +++ b/bip-0111.mediawiki @@ -0,0 +1,85 @@ +<pre> + BIP: 111 + Title: NODE_BLOOM service bit + Author: Matt Corallo <bip@bluematt.me>, Peter Todd <pete@petertodd.org> + Status: Draft + Type: Standards Track + Created: 2015-08-20 +</pre> + +== Abstract == + +This BIP extends BIP 37, Connection Bloom filtering, by defining a +service bit to allow peers to advertise that they support bloom filters +explicitly. It also bumps the protocol version to allow peers to +identify old nodes which allow bloom filtering of the connection despite +lacking the new service bit. + + +== Motivation == + +BIP 37 did not specify a service bit for the bloom filter service, thus +implicitly assuming that all nodes that serve peers data support it. +However, the connection filtering algorithm proposed in BIP 37, and +implemented in several clients today, has been shown to provide little +to no privacy<ref>http://eprint.iacr.org/2014/763</ref>, as well as being a large DoS risk on some nodes<ref>[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2013-July/003044.html] is one example where the issues were found, though others independently discovered issues as well. Sample DoS exploit code available at https://github.com/petertodd/bloom-io-attack.</ref>. +Thus, allowing node operators to disable connection bloom filtering is a +much-needed feature. + + +== Specification == + +The following protocol bit is added: + +<pre> + NODE_BLOOM = (1 << 2) +</pre> + +Nodes which support bloom filters should set that protocol bit. +Otherwise it should remain unset. In addition the protocol version is +increased from 70002 to 70011 in the reference implementation. It is +often the case that nodes which have a protocol version smaller than +70011, but larger than 70000 support bloom filtered connections without +the NODE_BLOOM bit set, however clients which require bloom filtered +connections should avoid making this assumption. + +NODE_BLOOM is distinct from NODE_NETWORK, and it is legal to advertise +NODE_BLOOM but not NODE_NETWORK (though there is little reason to do +so now, some proposals may make this more useful in the future) + +If a node does not support bloom filters but receives a "filterload", +"filteradd", or "filterclear" message from a peer the node should +disconnect that peer immediately. For backwards compatibility, in +initial implementations, nodes may choose to only disconnect nodes which +have the new protocol version set and attempt to send a filter command. + +While outside the scope of this BIP it is suggested that DNS seeds and +other peer discovery mechanisms support the ability to specify the +services required; current implementations simply check only that +NODE_NETWORK is set. + + +== Design rational == + +A service bit was chosen as applying a bloom filter is a service. + +The increase in protocol version is for backwards compatibility. In +initial implementations, old nodes which are not yet aware of NODE_BLOOM +and use a protocol version < 70011 may still send filter messages to a +node without NODE_BLOOM. This feature may be removed after there are +sufficient NODE_BLOOM nodes available and SPV clients have upgraded, +allowing node operators to fully close the bloom-related DoS vectors. + + +== Reference Implementation == + +https://github.com/bitcoin/bitcoin/pull/6579 + + +== Copyright == + +This document is placed in the public domain. + + +== References == +<references> diff --git a/bip-0112.mediawiki b/bip-0112.mediawiki new file mode 100644 index 0000000..c06caf5 --- /dev/null +++ b/bip-0112.mediawiki @@ -0,0 +1,246 @@ +<pre> + BIP: 112 + Title: CHECKSEQUENCEVERIFY + Authors: BtcDrak <btcdrak@gmail.com> + Mark Friedenbach <mark@friedenbach.org> + Status: Draft + Type: Standards Track + Created: 2015-08-10 +</pre> + +==Abstract== + +This BIP describes a new opcode (CHECKSEQUENCEVERIFY) for the Bitcoin +scripting system that in combination with BIP 68 allows execution +pathways of a script to be restricted based on the age of the output +being spent. + + +==Summary== + +CHECKSEQUENCEVERIFY redefines the existing NOP3 opcode. When executed +it compares the top item on the stack to the inverse of the nSequence +field of the transaction input containing the scriptSig. If the +inverse of nSequence is less than the sequence threshold (1 << 31), +the transaction version is greater than or equal to 2, and the top +item on the stack is less than or equal to the inverted nSequence, +script evaluation continues as though a NOP was executed. Otherwise +the script fails immediately. + +BIP 68's redefinition of nSequence prevents a non-final transaction +from being selected for inclusion in a block until the corresponding +input has reached the specified age, as measured in block height or +block time. By comparing the argument to CHECKSEQUENCEVERIFY against +the nSequence field, we indirectly verify a desired minimum age of the +the output being spent; until that relative age has been reached any +script execution pathway including the CHECKSEQUENCEVERIFY will fail +to validate, causing the transaction not to be selected for inclusion +in a block. + + +==Motivation== + +BIP 68 repurposes the transaction nSequence field meaning by giving +sequence numbers new consensus-enforced semantics as a relative +lock-time. However, there is no way to build Bitcoin scripts to make +decisions based on this field. + +By making the nSequence field accessible to script, it becomes +possible to construct code pathways that only become accessible some +minimum time after proof-of-publication. This enables a wide variety +of applications in phased protocols such as escrow, payment channels, +or bidirectional pegs. + + +==Specification== + +Refer to the reference implementation, reproduced below, for the precise +semantics and detailed rationale for those semantics. + + + // Threshold for nLockTime: below this value it is interpreted as block number, + // otherwise as UNIX timestamp (already defined in Bitcoin Core). + static const unsigned int LOCKTIME_THRESHOLD = 500000000; // Tue Nov 5 00:53:20 1985 UTC + + // Threshold for inverted nSequence: below this value it is interpreted + // as a relative lock-time, otherwise ignored. + static const uint32_t SEQUENCE_THRESHOLD = (1 << 31); + + case OP_NOP3: + { + if (!(flags & SCRIPT_VERIFY_CHECKSEQUENCEVERIFY)) { + // not enabled; treat as a NOP3 + if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) { + return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); + } + break; + } + + if (stack.size() < 1) + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); + + // Note that unlike CHECKLOCKTIMEVERIFY we do not need to + // accept 5-byte bignums since any value greater than or + // equal to SEQUENCE_THRESHOLD (= 1 << 31) will be rejected + // anyway. This limitation just happens to coincide with + // CScriptNum's default 4-byte limit with an explicit sign + // bit. + // + // This means there is a maximum relative lock time of 52 + // years, even though the nSequence field in transactions + // themselves is uint32_t and could allow a relative lock + // time of up to 120 years. + const CScriptNum nInvSequence(stacktop(-1), fRequireMinimal); + + // In the rare event that the argument may be < 0 due to + // some arithmetic being done first, you can always use + // 0 MAX CHECKSEQUENCEVERIFY. + if (nInvSequence < 0) + return set_error(serror, SCRIPT_ERR_NEGATIVE_LOCKTIME); + + // Actually compare the specified inverse sequence number + // with the input. + if (!CheckSequence(nInvSequence)) + return set_error(serror, SCRIPT_ERR_UNSATISFIED_LOCKTIME); + + break; + } + + bool CheckSequence(const CScriptNum& nInvSequence) const + { + int64_t txToInvSequence; + + // Fail under all circumstances if the transaction's version + // number is not set high enough to enable enforced sequence + // number rules. + if (txTo->nVersion < 2) + return false; + + // Sequence number must be inverted to convert it into a + // relative lock-time. + txToInvSequence = (int64_t)~txTo->vin[nIn].nSequence; + + // Sequence numbers under SEQUENCE_THRESHOLD are not consensus + // constrained. + if (txToInvSequence >= SEQUENCE_THRESHOLD) + return false; + + // There are two types of relative lock-time: lock-by- + // blockheight and lock-by-blocktime, distinguished by + // whether txToInvSequence < LOCKTIME_THRESHOLD. + // + // We want to compare apples to apples, so fail the script + // unless the type of lock-time being tested is the same as + // the lock-time in the transaction input. + if (!( + (txToInvSequence < LOCKTIME_THRESHOLD && nInvSequence < LOCKTIME_THRESHOLD) || + (txToInvSequence >= LOCKTIME_THRESHOLD && nInvSequence >= LOCKTIME_THRESHOLD) + )) + return false; + + // Now that we know we're comparing apples-to-apples, the + // comparison is a simple numeric one. + if (nInvSequence > txToInvSequence) + return false; + + return true; + } + +https://github.com/maaku/bitcoin/commit/33be476a60fcc2afbe6be0ca7b93a84209173eb2 + + +==Example: Escrow with Timeout== + +An escrow that times out automatically 30 days after being funded can be +established in the following way. Alice, Bob and Escrow create a 2-of-3 +address with the following redeemscript. + + IF + 2 <Alice's pubkey> <Bob's pubkey> <Escrow's pubkey> 3 CHECKMULTISIGVERIFY + ELSE + <LOCKTIME_THRESHOLD + 30*24*60*60> CHECKSEQUENCEVERIFY DROP + <Alice's pubkey> CHECKSIGVERIFY + ENDIF + +At any time funds can be spent using signatures from any two of Alice, +Bob or the Escrow. + +After 30 days Alice can sign alone. + +The clock does not start ticking until the payment to the escrow address +confirms. + + +==Reference Implementation== + +A reference implementation is provided in the following git repository: + +https://github.com/maaku/bitcoin/tree/checksequenceverify + + +==Deployment== + +We reuse the double-threshold switchover mechanism from BIPs 34 and +66, with the same thresholds, but for nVersion = 8. The new rules are +in effect for every block (at height H) with nVersion = 8 and at least +750 out of 1000 blocks preceding it (with heights H-1000..H-1) also +have nVersion = 8. Furthermore, when 950 out of the 1000 blocks +preceding a block do have nVersion = 8, nVersion = 3 blocks become +invalid, and all further blocks enforce the new rules. + +When assessing the block version as mask of ~0x20000007 must be applied +to work around the complications caused by +[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010396.html BIP101's premature use] +of the [https://gist.github.com/sipa/bf69659f43e763540550 undecided version bits proposal]. + +By applying ~0x20000007 with nVersion = 8, the thresholds should be tested +comparing block nVersion >= 4 as this will save a bit for future use. + +It is recommended that this soft-fork deployment trigger include other +related proposals for improving Bitcoin's lock-time capabilities, including: + +[https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP 65]: +OP_CHECKLOCKTIMEVERIFY, + +[https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP 68]: +Consensus-enforced transaction replacement signalled via sequence numbers, + +and [https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki BIP 113]: +Median-Past-Time-Lock. + +==Credits== + +Mark Friedenbach invented the application of sequence numbers to +achieve relative lock-time, and wrote the reference implementation of +CHECKSEQUENCEVERIFY. + +The reference implementation and this BIP was based heavily on work +done by Peter Todd for the closely related BIP 65. + +BtcDrak authored this BIP document. + + +==References== + +BIP 68: Consensus-enforced transaction replacement signalled via +sequence numbers +https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki + +BIP 65: OP_CHECKLOCKTIMEVERIFY +https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki + +BIP 113: Median past block time for time-lock constraints +https://github.com/bitcoin/bips/blob/master/bip-0113.mediawiki + +HTLCs using OP_CHECKSEQUENCEVERIFY/OP_LOCKTIMEVERIFY and +revocation hashes +http://lists.linuxfoundation.org/pipermail/lightning-dev/2015-July/000021.html + +[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010396.html Softfork deployment considerations] + +[https://gist.github.com/sipa/bf69659f43e763540550 Version bits] + + +==Copyright== + +This document is placed in the public domain. diff --git a/bip-0113.mediawiki b/bip-0113.mediawiki new file mode 100644 index 0000000..b7313e3 --- /dev/null +++ b/bip-0113.mediawiki @@ -0,0 +1,137 @@ +<pre> + BIP: 113 + Title: Median time-past as endpoint for lock-time calculations + Author: Thomas Kerin <me@thomaskerin.io> + Mark Friedenbach <mark@friedenbach.org> + Status: Draft + Type: Standards Track + Created: 2015-08-10 +</pre> + + +==Abstract== + +This BIP is a proposal to redefine the semantics used in determining a +time-locked transaction's eligibility for inclusion in a block. The +median of the last 11 blocks is used instead of the block's timestamp, +ensuring that it increases monotonically with each block. + + +==Motivation== + +At present, transactions are excluded from inclusion in a block if the +present time or block height is less than or equal to that specified +in the locktime. Since the consensus rules do not mandate strict +ordering of block timestamps, this has the unfortunate outcome of +creating a perverse incentive for miners to lie about the time of +their blocks in order to collect more fees by including transactions +that by wall clock determination have not yet matured. + +This BIP proposes comparing the locktime against the median of the +past 11 block's timestamps, rather than the timestamp of the block +including the transaction. Existing consensus rules guarantee this +value to monotonically advance, thereby removing the capability for +miners to claim more transaction fees by lying about the timestamps of +their block. + +This proposal seeks to ensure reliable behaviour in locktime calculations as +required by BIP65 (CHECKLOCKTIMEVERIFY), BIP68, and BIP112 (CHECKSEQUENCEVERIFY). + + +==Specification== + +The values for transaction locktime remain unchanged. The difference is only in +the calculation determining whether a transaction can be included. Instead of +an unreliable timestamp, the following function is used to determine the current +block time for the purpose of checking lock-time constraints: + + enum { nMedianTimeSpan=11 }; + + int64_t GetMedianTimePast(const CBlockIndex* pindex) + { + int64_t pmedian[nMedianTimeSpan]; + int64_t* pbegin = &pmedian[nMedianTimeSpan]; + int64_t* pend = &pmedian[nMedianTimeSpan]; + for (int i = 0; i < nMedianTimeSpan && pindex; i++, pindex = pindex->pprev) + *(--pbegin) = pindex->GetBlockTime(); + std::sort(pbegin, pend); + return pbegin[(pend - pbegin)/2]; + } + +Lock-time constraints are checked by the consensus method IsFinalTx(), +or LockTime() under BIP68. These methods take the block time as one +parameter. This BIP proposes that after activation calls to +IsFinalTx() or LockTime() within consensus code use the return value +of `GetMedianTimePast(pindexPrev)` instead. + +A reference implementation of this proposal is provided in the +following git repository: + +https://github.com/maaku/bitcoin/tree/medianpasttimelock + + +==Deployment== + +We reuse the double-threshold switchover mechanism from BIPs 34 and +66, with the same thresholds, but for nVersion = 8. The new rules are +in effect for every block (at height H) with nVersion = 8 and at least +750 out of 1000 blocks preceding it (with heights H-1000..H-1) also +have nVersion = 8. Furthermore, when 950 out of the 1000 blocks +preceding a block do have nVersion = 8, nVersion = 3 blocks become +invalid, and all further blocks enforce the new rules. + +When assessing the block version as mask of ~0x20000007 must be applied +to work around the complications caused by +[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010396.html BIP101's premature use] +of the [https://gist.github.com/sipa/bf69659f43e763540550 undecided version bits proposal]. + +By applying ~0x20000007 with nVersion = 8, the thresholds should be tested +comparing block nVersion >= 4 as this will save a bit for future use. + +It is recommended that this soft-fork deployment trigger include other related +proposals for improving Bitcoin's lock-time capabilities, including: + +[https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP 65]: +CHECKLOCKTIMEVERIFY, + +[https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP 68]: +Consensus-enforced transaction replacement signalled via sequence numbers, + +and [https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki BIP 112]: +CHECKSEQUENCEVERIFY. + + +==Acknowledgements== + +Mark Friedenbach for designing and authoring the reference +implementation of this BIP. + +Thanks go to Gregory Maxwell who came up with the original idea, +in #bitcoin-wizards on 2013-07-16. + +Thomas Kerin authored this BIP document. + + +==Compatibility== + +Transactions generated using time-based lock-time will take +approximately an hour longer to confirm than would be expected under +the old rules. This is not known to introduce any compatibility +concerns with existing protocols. + + +==References== +[https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki BIP65: OP_CHECKLOCKTIMEVERIFY] + +[https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki BIP68: Consensus-enforced transaction replacement signaled via sequence numbers] + +[https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki BIP112: CHECKSEQUENCEVERIFY] + +[http://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-August/010396.html Softfork deployment considerations] + +[https://gist.github.com/sipa/bf69659f43e763540550 Version bits] + + +==Copyright== + +This document is placed in the public domain. diff --git a/bip-0120.mediawiki b/bip-0120.mediawiki new file mode 100644 index 0000000..e099f5b --- /dev/null +++ b/bip-0120.mediawiki @@ -0,0 +1,152 @@ +<pre> + BIP: 120 + Title: Proof of Payment + Author: Kalle Rosenbaum <kalle@rosenbaum.se> + Status: Draft + Type: Standards Track + Created: 2015-07-28 +</pre> + +== Abstract == + +This BIP describes a system called Proof of Payment, PoP. It is used to prove that a wallet has the credentials that were used to sign a previously generated transaction. Or simply put, it lets you prove that you have made a payment. + +== Motivation == + +There are several scenarios in which it would be useful to prove that you have paid for something. For example: + +* A pre-paid hotel room where your PoP functions as a key to the door. +* An online video rental service where you pay for a video and watch it on any device. +* An ad-sign where you pay in advance for e.g. 2 weeks exclusivity. During this period you can upload new content to the sign whenever you like using PoP. +* Log in to a pay site using a PoP. +* A parking lot you pay for monthly and the car authenticates itself using PoP. +* A lottery where all participants pay to the same address, and the winner is selected among the transactions to that address. You exchange the prize for a PoP for the winning transaction. + +With Proof of Payment, these use cases can be achieved without any personal information (user name, password, e-mail address, etc) being involved. + +== Rationale == + +Desirable properties: + +# A PoP should be generated on demand. +# It should only be usable once to avoid issues due to theft. +# It should be able to create a PoP for any payment, regardless of script type (P2SH, P2PKH, etc.). +# It should prove that you have enough credentials to unlock all the inputs of the proven transaction. +# It should be easy to implement by wallets and servers to ease adoption. + +Current methods of proving a payment: + +* In BIP0070, the PaymentRequest together with the transactions fulfilling the request makes some sort of proof. However, it does not meet 1, 2 or 4 and it obviously only meets 3 if the payment is made through BIP0070. Also, there's no standard way to request/provide the proof. If standardized it would probably meet 5. +* Signing messages, chosen by the server, with the private keys used to sign the transaction. This could meet 1 and 2 but probably not 3. This is not standardized either. 4 Could be met if designed so. + +If an input script type is P2SH, any satisfying script should do, just as if it was a payment. For M-of-N multisig scripts, that would mean that any set of M keys should be sufficient, not neccesarily the same set of M keys that signed the transaction. This is important because strictly demanding the same set of M keys would defeat the purpose of a multisig address. + +== Specification == + +=== Data structure === + +A proof of payment for a transaction T, here called PoP(T), is used to prove that one has ownership of the credentials needed to unlock all the inputs of T. It has the exact same structure as a bitcoin transaction with the same inputs as T and in the same order as in T, but with each sequence number set to 0. There is exactly one output, here called the pop output, with value 0. The pop output must have the following format: + + OP_RETURN <version> <txid> <nonce> + +{| +! Field !! Size [B] !! Description +|- +| <version> || 2 || Version, little endian, currently 0x01 0x00 +|- +| <txid> || 32 || The transaction to prove +|- +| <nonce> || 6 || Random data +|} + +The lock_time of the PoP must be set to 499999999 to prevent the PoP from being included in a block, should it appear on the bitcoin p2p network. This is also the reason for setting the sequence numbers to 0, since sequence number of ffffffff would make lock_time ineffective. This specification demands that all input sequence numbers are 0, not just one of them, which would be sufficient to make lock_time effective. This is for simplicity reasons. + +An illustration of the PoP data structure and its original payment is shown below. + +<pre> + T + +------------------------------------------------+ + |inputs | outputs | + | Value,Sequence | Value,Script | + +------------------------------------------------+ + |input0 1,ffffffff | 0,pay to A | + |input1 3,ffffffff | 2,OP_RETURN <some data> | + |input2 4,ffffffff | 1,pay to B | + | | 4,pay to C | + +------------------------------------------------+ + + PoP(T) + +-------------------------------------------------------------+ + | inputs | outputs | + | Value,Sequence | Value,Script | + +-------------------------------------------------------------+ + |input0 1,00000000 | 0,OP_RETURN <version> <txid> <nonce> | + |input1 3,00000000 | | + |input2 4,00000000 | | + +-------------------------------------------------------------+ + | lock_time=499999999 | + +-------------------------------------------------------------+ +</pre> + +The PoP is signed using the same signing process that is used for bitcoin transactions. + +The purpose of the nonce is to make it harder to use a stolen PoP; Once the PoP has reached the server, that PoP is useless since the server will generate a new nonce for every PoP request. + +=== Process === + +# A proof of payment request is sent from the server to the wallet. The PoP request contains: +## a random nonce +## a destination where to send the PoP, for example a https URL +## data hinting the wallet which transaction to create a proof for. For example: +##* txid, if known by the server +##* PaymentRequest.PaymentDetails.merchant_data (in case of a BIP0070 payment) +##* amount, label, message or other information from a BIP0021 URI +# The wallet identifies a transaction T, if possible. Otherwise it asks the user to select among the ones that match the hints in 1.iii. +# The wallet creates an unsigned PoP (UPoP) for T, and asks the user to sign it. +# The user confirms +# The UPoP(T) is signed by the wallet, creating PoP(T). +# The PoP is sent to the destination in 1.ii. +# The server receiving the PoP validates it and responds with “valid” or “invalid”. +# The wallet displays the response in some way to the user. + +'''Remarks:''' + +* The method of transferring the PoP request at step 1 is not specified here. Instead that is specified in separate specifications, see BIP0121. +* The nonce must be randomly generated by the server for every new PoP request. + +=== Validating a PoP === + +The server needs to validate the PoP and reply with "valid" or "invalid". That process is outlined below. If any step fails, the validation is aborted and "invalid" is returned: + +# Check the format of the PoP. It must pass normal transaction checks, except that the inputs may already be spent. +# Check that lock_time is 499999999. +# Check that there is exactly one output. This output must have value 0 and conform to the OP_RETURN output format outlined above. +# Check that the nonce is the same as the one requested. +# Check that the inputs of the PoP are exactly the same as in transaction T, except that the sequence numbers must all be 0. The ordering of the inputs must also be the same as in T. +# Run the scripts of all the inputs. All scipts must return true. +# Check that the txid in the PoP output is the transaction you actually want proof for. If you don’t know exactly what transaction you want proof for, check that the transaction actually pays for the product/service you deliver. +# Return "valid". + +== Security considerations == + +* Someone can intercept the PoP-request and change any parameter in it. These can be mitigated by using secure connections. Examples of tampered parameters: +** Pop destination - Stealing your PoP. +** label - Trick you to sign an unintended pop or set a label that your wallet doesn't have any record for, resulting in a broken service. Always check the PoP before signing. +** nonce - Your pop will not validate on server. +* Someone can steal a PoP, for example by tampering with the PoP request, and try to use the service hoping to get a matching nonce. Probability per try: 1/(2^48). The server should have a mechanism for detecting a brute force attack of this kind, or at least slow down the process by delaying the PoP request by some 100 ms or so. +* Even if a wallet has no funds it might still be valuable as a generator for PoPs. This makes it important to keep the security of the wallet after it has been emptied. +* Transaction malleability may cause the server to have another transaction id for a payment than the client's wallet. In that case the wallet will not be able to prove the transaction to the server. Wallets should not rely on the transaction id of the outgoing transaction. Instead it should listen for the transaction on the network and put that in its list of transactions. + +== Reference implementation == + +[https://github.com/kallerosenbaum/poppoc PoP Demo server on GitHub] + +[https://github.com/kallerosenbaum/wallet PoP-enabled Mycelium fork on GitHub] + +== References == + +[https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki BIP0021]: URI Scheme + +[https://github.com/bitcoin/bips/blob/master/bip-0070.mediawiki BIP0070]: Payment Protocol + +[https://github.com/bitcoin/bips/blob/master/bip-0121.mediawiki BIP0121]: Proof of Payment URI scheme diff --git a/bip-0121.mediawiki b/bip-0121.mediawiki new file mode 100644 index 0000000..76513dd --- /dev/null +++ b/bip-0121.mediawiki @@ -0,0 +1,146 @@ +<pre> + BIP: 121 + Title: Proof of Payment URI scheme + Author: Kalle Rosenbaum <kalle@rosenbaum.se> + Status: Draft + Type: Standards Track + Created: 2015-07-27 +</pre> + +== Abstract == + +This is a proposal for a URI scheme to be used in the Proof of Payment +process. + +== Motivation == + +To make a Proof of Payment, the party that wants the proof needs to +transfer a Proof of Payment request to the wallet software of the +other party. To facilitate that transfer, a new URI scheme +representing the PoP request is proposed. This URI can then be encoded +in QR images or be sent over NFC in order to transfer it to the wallet. + +== Specification == + +The specification is the same as BIP0021, with the following +differences: + +* The URI scheme is <tt>btcpop</tt> instead of <tt>bitcoin</tt> +* The path component, i.e. the address part, is always empty. +* A mandatory <tt>p</tt> parameter whose value contains the destination for the PoP. This could for example be a <tt>https:</tt> URL or a <tt>mailto:</tt> URI. +* A mandatory <tt>n</tt> parameter representing the nonce, base58 encoded. +* An optional <tt>txid</tt> parameter containing the Base58 encoded hash of the transaction to prove. + +Just as in BIP0021, elements of the query component may contain +characters outside the valid range. These must first be encoded +according to UTF-8, and then each octet of the corresponding UTF-8 +sequence must be percent-encoded as described in RFC 3986. + +All parameters except <tt>p</tt> and <tt>n</tt> are hints to the +wallet on which transaction to create a PoP for. + +The extensibility of BIP0021 applies to this scheme as well. For +example, a <tt>date</tt> parameter or a <tt>toaddr</tt> parameter +might be useful. <tt>req-*</tt> parameters are also allowed and obey +the same rules as in BIP0021, clients not supporting a <tt>req-*</tt> +parameter must consider the URI invalid. + +=== Keep URIs short === + +Implementations should keep the URIs as short as possible. This is +because it makes QR decoding more stable. A camera with a scratched +lens or low resolution may run into problems scanning huge QR +codes. This is why the <tt>txid</tt> parameter is encoded in Base58 +instead of the classic hex encoded string. We get away with 44 +characters instead of 64. Also, the <tt>nonce</tt> parameter is Base58 +encoded for the same reason. + +== Interpretation == + +=== Transaction hints === + +The wallet processing the URI must use the hints in the PoP request to +filter its transaction set. The <tt>label</tt>, <tt>amount</tt> and +<tt>message</tt> parameters must, if present in the URI, exactly match +the data associated with the original payment according to the +following table: + +{| +| <tt>btcpop:</tt> URI parameter || <tt>bitcoin:</tt> URI parameter || BIP70 PaymentDetails data +|- +| <tt>label</tt> || <tt>label</tt> || <tt>merchant_data</tt> +|- +| <tt>amount</tt> || <tt>amount</tt> || <tt>sum of outputs.amount</tt> +|- +| <tt>message</tt> || <tt>message</tt> || <tt>memo</tt> +|} + +The <tt>txid</tt> parameter value must match the transaction hash of +the payment. + +After filtering, the resulting transaction set is displayed to the +user who selects one of them to prove. An implementation could also +automatically select a transaction in the filtered set, but +there must still be a way for the user to select freely among the +matching transactions. If the filtered set is empty, no transaction +fits the hints and a message about that is presented to the user. If +the filtered set contains exactly one transaction, which is +preferable, that transaction can be automatically selected. + +As a fallback, there must also be a way for the user to select any +transaction from the wallet regardless of the transaction hints. This +can be useful if the metadata of the wallet is lost, possibly due to a +restore from backup. + +=== PoP destination <tt>p</tt> === + +The <tt>p</tt> parameter value is the destination where to send the +PoP to. This destination is typically a <tt>https:</tt> URL or a +<tt>http:</tt> URL, but it could be any type of URI, for example +<tt>mailto:</tt>. To keep <tt>btcpop:</tt> URIs short, users should +not make their <tt>p</tt> parameter unneccesarily long. + +==== <tt>http:</tt> and <tt>https:</tt> URLs ==== + +Wallet implementations must support the <tt>http:</tt> and +<tt>https:</tt> schemes in which case <tt>POST</tt> method must be +used. The content type of the POST request must be set to + + Content-Type: application/bitcoin-pop + Content-Transfer-Encoding: binary + +== Examples == + +Send PoP for a transaction with label "video 42923" to +<nowiki>https://www.example.com/pop/352</nowiki>, using nonce +<tt>0x73 0xd5 0x1a 0xbb 0xd8 0x9c</tt>: +<pre> + btcpop:?p=https://www.example.com/pop/352&n=zgWTm8yH&label=video 42923 +</pre> +Send PoP through mail using +<nowiki>mailto:pop@example.com?subject=pop444</nowiki>, amount +is 13370000 satoshis, nonce is <tt>0x6f 0xe 0xfb 0x68 0x92 0xf9</tt>. +Note that the <tt>?</tt> before <tt>subject</tt> is OK according to RFC3986, +since the query part starts from the first <tt>?</tt>: +<pre> + btcpop:?p=mailto:pop@example.com?subject%3Dpop444&n=xJdKmEbr&amount=0.1337 +</pre> +Send PoP for transaction with id +<tt>cca7507897abc89628f450e8b1e0c6fca4ec3f7b34cccf55f3f531c659ff4d79</tt> +to pizza place at <nowiki>http://pizza.example.com/pop/laszlo111</nowiki> using nonce <tt>0xfc 0xcc 0x2c 0x35 0xf0 0xb8</tt> +<pre> + btcpop:?p=http://pizza.example.com/pop/laszlo111&n=3AtNpVrPh&txid=Emt9MPvt1joznqHy5eEHkNtcuQuYWXzYJBQZN6BJm6NL +</pre> +== Reference implementation == + +[https://github.com/kallerosenbaum/poppoc PoP Demo server on GitHub] + +[https://github.com/kallerosenbaum/wallet PoP-enabled Mycelium fork on GitHub] + +== References == + +[https://github.com/bitcoin/bips/blob/master/bip-0021.mediawiki BIP0021]: URI Scheme + +[https://github.com/bitcoin/bips/blob/master/bip-0120.mediawiki BIP0120]: Proof of Payment + +[https://www.ietf.org/rfc/rfc3986.txt RFC3986]: Uniform Resource Identifier (URI): Generic Syntax |
