{"id":54696,"date":"2025-10-24T16:01:36","date_gmt":"2025-10-24T16:01:36","guid":{"rendered":"https:\/\/dogewisperer.com\/?p=54696"},"modified":"2025-10-24T16:01:36","modified_gmt":"2025-10-24T16:01:36","slug":"new-bitcoin-improvement-proposal-aims-to-improve-privacy-heres-how","status":"publish","type":"post","link":"https:\/\/dogewisperer.com\/?p=54696","title":{"rendered":"New Bitcoin Improvement Proposal Aims To Improve Privacy: Here\u2019s How"},"content":{"rendered":"
\n

A new Bitcoin Improvement Proposal titled \u201cChain Code Delegation for Private Collaborative Custody\u201d has been opened on the Bitcoin BIPs repository, targeting a long-standing privacy leak in multisig collaborations that rely on shared extended public keys.<\/p>\n

The technique, authored by Bitkey engineers and collaborators, with a public explainer from Bitkey, proposes withholding BIP32 chain codes from non-privileged participants so that cosigners can help with recovery and policy enforcement without gaining sweeping visibility into a user\u2019s balances and transaction history. Bitkey says it plans to implement the scheme first if it becomes an accepted standard.<\/p>\n

How The BIP Enhances Bitcoin Privacy<\/h2>\n

The crux of the privacy problem is well known to wallet engineers and custodial partners: in typical collaborative or assisted multisig<\/a>, the cosigner is handed an xpub plus chain code, which lets them deterministically derive the addresses in a user\u2019s wallet and, by scanning the blockchain, infer balances and flows.<\/p>\n

Bitkey\u2019s post<\/a> frames the status quo plainly: sharing a key with a third party has \u201ctraditionally meant giving that party visibility into a user\u2019s wallet balance and transaction history.\u201d The new approach, they argue, \u201caims to remove that tradeoff\u201d by withholding chain codes entirely and revealing only what is minimally necessary at spend time.<\/p>\n

The proposed BIP\u2019s abstract is crisp about the change in trust boundaries: \u201cWe propose a new BIP for Chain Code Delegation, a collaborative custody technique that involves privileged participants (delegatee) withholding BIP32 chain codes at key setup time from a delegator, and sharing only enough information for non-privileged participants to provide their signature.\u201d<\/p>\n

In the non-blinded flow, \u201cthe delegatee derives a per-spend scalar tweak t from the (withheld) chain code, the delegator computes the child key (x+t, P+tG), and produces a standard signature over the transaction\u2019s sighash.\u201d The blinded flow layers Schnorr blind signing on top so that the cosigner remains oblivious to the final message while still enforcing the per-spend tweak, leveraging the linearity of Schnorr for correctness.<\/p>\n

Functionally, the technique narrows what a cosigner can learn and when. Rather than permanent, global observability over all derived addresses, the cosigner only sees per-spend data as needed. The Bitkey explainer translates this into a user-facing promise: cosigners can assist with recovery or spend policies \u201cwithout learning anything about unrelated transactions or overall balances.\u201d<\/p>\n

If widely adopted, that shift would make collaborative custody wallets more comparable to DIY multisig on privacy, while preserving the operational benefits that have made assisted models attractive to mainstream and enterprise users.<\/p>\n

The design has been incubating in the open. A technical discussion thread on Delving Bitcoin over the summer summarized two key benefits that extend beyond privacy: limiting the \u201csecurity blast radius\u201d because, without the chain code or undisclosed tweaks, a custodian\u2019s key is effectively unspendable for UTXOs they haven\u2019t been explicitly delegated for; and tightly scoping what gets revealed at the moment of spend, often just before those outputs are consumed. That thread foreshadowed the BIP now filed and offers useful context for reviewers tracing how the proposal hardened through feedback.<\/p>\n

Bitkey positions itself<\/a>\u00a0as the first mover on implementation once the standard is vetted. \u201cBitkey plans to be the first to implement Chain Code Delegation in production,\u201d the company wrote, arguing that it will enable \u201ca private collaborative wallet\u2014something that hasn\u2019t been possible until now.\u201d The explicit intention is for the technique to be an \u201copen, community-vetted standard that any wallet or custody provider can adopt,\u201d not a vendor-locked feature.<\/p>\n

Prominent industry accounts amplified the announcement on X. Principal executive officer and chairman of Block, Inc Jack Dorsey<\/a> highlighted Bitkey\u2019s focus on pushing privacy improvements from product to protocol.<\/p>\n

At press time, Bitcoin traded at $111,398.<\/p>\n

\"Bitcoin<\/div>\n","protected":false},"excerpt":{"rendered":"

A new Bitcoin Improvement Proposal titled \u201cChain Code Delegation for Private Collaborative Custody\u201d has been opened on the Bitcoin BIPs repository, targeting a long-standing privacy leak in multisig collaborations that rely on shared extended public keys. The technique, authored by Bitkey engineers and collaborators, with a public explainer from Bitkey, proposes withholding BIP32 chain codes […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":0,"footnotes":""},"categories":[2],"tags":[3,4,5],"class_list":["post-54696","post","type-post","status-publish","format-standard","hentry","category-news","tag-crypto","tag-doge","tag-news"],"_links":{"self":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/posts\/54696","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=54696"}],"version-history":[{"count":0,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=\/wp\/v2\/posts\/54696\/revisions"}],"wp:attachment":[{"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=54696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=54696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dogewisperer.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=54696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}