{"number":81,"title":"Hierarchy for Colored Voting Pool Deterministic Multisig Wallets","authors":["Justus Ranvier","Jimmy Song"],"status":"Closed","type":"Informational","created":"2014-08-11","license":"PD","requires":[],"replaces":[],"replacedBy":[],"discussion":[],"abstract":"This BIP defines a logical hierarchy for colored coin voting pool deterministic multisig wallets based on an algorithm described in BIP-0032 (BIP32 from now on) and purpose scheme described in BIP-0043 (BIP43 from now on). This BIP is a particular application of BIP43 and is based on BIP44.","eli5":"A companion to BIP 80, this proposal defines a standard key structure for voting pool multisignature wallets that handle 'colored coins', bitcoins tagged to represent other assets. Following a common layout lets different wallet software consistently generate and track the same addresses.","categories":["wallets"],"filename":"bip-0081.mediawiki","githubUrl":"https://github.com/bitcoin/bips/blob/master/bip-0081.mediawiki","format":"mediawiki","readingMinutes":2,"inbound":1,"revisions":14,"impact":49,"core":false,"references":[32,43,44,80],"lastModified":"2025-10-08","html":"<h2 id=\"abstract\">Abstract</h2>\n<p>This BIP defines a logical hierarchy for colored coin voting pool deterministic multisig wallets based on an algorithm described in BIP-0032 (BIP32 from now on) and purpose scheme described in BIP-0043 (BIP43 from now on).</p>\n<p>This BIP is a particular application of BIP43 and is based on BIP44.</p>\n<h2 id=\"motivation\">Motivation</h2>\n<p>The hierarchy proposed in this paper allows the handling of multiple color definitions from a single seed.</p>\n<h2 id=\"path-levels\">Path levels</h2>\n<p>We define the following 8 levels in BIP32 path:</p>\n<pre><code>m / purpose' / series' / (5 color definition levels) / address_index</code></pre>\n<p>Apostrophe in the path indicates that BIP32 hardened derivation is used.</p>\n<p>Each level has a special meaning, described in the chapters below.</p>\n<h3 id=\"purpose\">Purpose</h3>\n<p>Purpose is a constant set following the BIP43 recommendation to: the ASCII value of \"81\" with the most significant bit set to indicate hardened derivation (0x80000051). It indicates that the subtree of this node is used according to this specification.</p>\n<p>Hardened derivation is used at this level.</p>\n<h3 id=\"color-definition\">Color Definition</h3>\n<p>Index values which can be applied to a BIP32 node are limited to 4 bytes (32 bits).</p>\n<p>Since this is not sufficient to identify color definitions without a risk of collision, multiple levels are used.</p>\n<p>Color definitions are first shortened to 20 bytes using the Bitcoin hash160 function.</p>\n<p>The resulting 20 bytes are split into five groups in little endian format, and where each group is used as the seed for the five levels of color definition levels</p>\n<p>Public derivation is used at these levels, even when the index exceeds 2^31.</p>\n<h3 id=\"index\">Index</h3>\n<p>Public/private keypairs are numbered from index 0 in sequentially increasing manner. This number is used as child index in BIP32 derivation.</p>\n<p>Public keys obtained at this level of the hierarchy are used to construct multisig deposit scripts, using a schema that is shared between the members as an out-of-band contract.</p>\n<p>Public derivation is used at this level.</p>\n<h2 id=\"compatible-wallets\">Compatible wallets</h2>\n<ul><li>\n<a href=\"https://github.com/btcsuite/btcwallet\">btcwallet</a> is the reference Bitcoin wallet for voting pools.\n</li></ul>\n<h2 id=\"copyright\">Copyright</h2>\n<p>This document is placed in the public domain.</p>\n<h2 id=\"reference\">Reference</h2>\n<ul><li>\n<a href=\"/bip/32\">BIP32 - Hierarchical Deterministic Wallets</a>\n</li></ul>\n<ul><li>\n<a href=\"/bip/43\">BIP43 - Purpose Field for Deterministic Wallets</a>\n</li></ul>\n<ul><li>\n<a href=\"/bip/44\">BIP44 - Multi-Account Hierarchy for Deterministic Wallets</a>\n</li></ul>\n<ul><li>\n<a href=\"/bip/80\">BIP80 - Hierarchy for Non-Colored Voting Pool Deterministic Multisig Wallets</a>\n</li></ul>","toc":[{"id":"abstract","title":"Abstract","level":2},{"id":"motivation","title":"Motivation","level":2},{"id":"path-levels","title":"Path levels","level":2},{"id":"purpose","title":"Purpose","level":3},{"id":"color-definition","title":"Color Definition","level":3},{"id":"index","title":"Index","level":3},{"id":"compatible-wallets","title":"Compatible wallets","level":2},{"id":"copyright","title":"Copyright","level":2},{"id":"reference","title":"Reference","level":2}],"history":{"totalCommits":14,"firstCommit":"2015-06-19T18:14:36-05:00","lastUpdated":"2025-10-08T14:59:36-07:00","events":[{"sha":"24e96e870fffaa257b465ce1f0370c14aac588e8","date":"2025-10-08T14:59:36-07:00","author":"Murch","message":"process: Created ↦ Assigned","url":"https://github.com/bitcoin/bips/commit/24e96e870fffaa257b465ce1f0370c14aac588e8","kind":"edit"},{"sha":"5207ef92a52d0b8902895b0dbb40823a4d698ec9","date":"2025-04-11T20:08:17-07:00","author":"Murch","message":"process: Author ↦ Authors","url":"https://github.com/bitcoin/bips/commit/5207ef92a52d0b8902895b0dbb40823a4d698ec9","kind":"edit"},{"sha":"59730dec4fb641a41589aa1b91d3c452f13e0e36","date":"2025-04-11T20:05:13-07:00","author":"Murch","message":"process: Remove Comments-URI and -Summary","url":"https://github.com/bitcoin/bips/commit/59730dec4fb641a41589aa1b91d3c452f13e0e36","kind":"edit"},{"sha":"66defbdc03ad64ccddfd373e1c59af9a41ab990f","date":"2025-04-11T18:11:55-07:00","author":"Murch","message":"process: Deferred/Obsolete/Rejected/Replaced/Withdrawn ↦ Closed","url":"https://github.com/bitcoin/bips/commit/66defbdc03ad64ccddfd373e1c59af9a41ab990f","kind":"status"},{"sha":"2d9e431fbe654640b55bca3bf8c4b17462890109","date":"2024-04-30T14:51:39-04:00","author":"Varunram Ganesh","message":"[trivial]: Correct spellings across bips (#675)","url":"https://github.com/bitcoin/bips/commit/2d9e431fbe654640b55bca3bf8c4b17462890109","kind":"edit"},{"sha":"6295c1a095a1fa33f38d334227fa4222d8e0a523","date":"2017-08-24T23:50:20+12:00","author":"MeshCollider","message":"Fixing spelling in multiple BIPs","url":"https://github.com/bitcoin/bips/commit/6295c1a095a1fa33f38d334227fa4222d8e0a523","kind":"edit"},{"sha":"959fecc15bdad070afa63455468b1dba54655fa6","date":"2016-11-30T09:47:31+00:00","author":"Luke Dashjr","message":"Promote BIP 2 Draft->Active, and implement it","url":"https://github.com/bitcoin/bips/commit/959fecc15bdad070afa63455468b1dba54655fa6","kind":"status"},{"sha":"387fc6011bd804609fd751786e50439d5c11a097","date":"2016-08-23T19:47:29+00:00","author":"Luke Dashjr","message":"Promote BIPs 18, 39, 44, 67, 80, 81, 111, 125, 130, and 132 Draft->Accepted; 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