Part of the CustodyStress archive of observed Bitcoin custody incidents
Multisig quorum failure
Cases in this category involve multisig arrangements where the required number of signers was not available to authorize a transaction.
Multisig quorum failures arise when the signing threshold cannot be reached due to key holder unavailability, not due to key loss. Cases span personal inheritance setups, corporate treasury arrangements, and protocol-level governance structures. The common pattern is a quorum requirement designed for security that becomes a coordination barrier when key holders are unavailable, unresponsive, or in dispute.
77 observed cases
Blocked
5 (6%)
Constrained
7 (9%)
Survives
56 (73%)
Indeterminate
9 (12%)
The trustee firm merged with a competitor in June 2017 and the key was migrated to
Exchange custody
A Bitcoin inheritance arrangement using a 1-of-2 multisig designed for survivorship had a key held by a professional trustee. The trustee firm merged with a com
The fund's BTC was inaccessible for two months while negotiations continued.
Exchange custody
A Bitcoin venture fund's treasury was held in a 3-of-5 multisig. In April 2017 the fund underwent a restructuring in which two key holders were removed without
Two admins resigned simultaneously following a governance dispute, leaving only three
Mobile or software wallet
A Bitcoin community project used a 3-of-5 multisig treasury managed by five volunteer administrators across five countries. In March 2017 two admins resigned si
Multisig quorum failure — 2-of-3 multisig (2017)
Mobile or software wallet
An October 2017 forum case describes a three-person Bitcoin partnership that held funds in a 2-of-3 multisig. One partner died suddenly, leaving the surviving t
The attorney retired suddenly in November 2016 and transferred their practice.
Mobile or software wallet
A Bitcoin escrow arrangement for a business acquisition used a 2-of-3 multisig. One key was held by the buyer, one by the seller, and one by an escrow attorney.
Multisig quorum failure — 3-of-5 multisig (2016)
Mobile or software wallet
A June 2016 forum case describes a startup that used a 3-of-5 multisig for its Bitcoin treasury. The company went through a hostile acquisition and three of the
Multisig quorum failure — 2-of-3 multisig (2016)
Exchange custody
A venture capital fund that stored its Bitcoin portfolio in a 2-of-3 multisig lost one key when a general partner's laptop was seized by authorities during an u
Multisig quorum failure — software wallet 2016
Mobile or software wallet
A Bitcoin foundation that used a 3-of-5 board-controlled multisig for its treasury faced a quorum failure in January 2016 when two board members resigned simult
The MDM policy wiped the wallet app and its stored key.
Mobile or software wallet
A Bitcoin company treasury held in 2-of-3 Copay multisig experienced a quorum failure in February 2016 when a key holder's device was remotely wiped as part of
Multisig quorum failure — software wallet 2016
Mobile or software wallet
A Bitcoin inheritance arrangement structured as a 1-of-2 multisig (for survivorship) was challenged in court in September 2016. The deceased had created the 2-o
Multisig quorum failure — software wallet 2015
Mobile or software wallet
A Bitcoin inheritance arrangement used a 2-of-3 multisig where the testator held two keys and a trusted friend held the third. The testator became seriously ill
Multisig quorum failure — software wallet (2015)
Mobile or software wallet
A partnership that had set up a 3-of-5 cold storage arrangement in 2013 attempted to access funds in July 2015. Of the five key holders, one had died, one was u
Multisig quorum failure — 2-of-3 multisig (2015)
Exchange custody
A Bitcoin escrow startup that had implemented a 2-of-3 multisig for all escrows lost access to its hosted key when its cloud HSM provider underwent an emergency
Multisig quorum failure — 2-of-3 multisig (2015)
Mobile or software wallet
A 2015 case documents a Bitcoin attorney escrow arrangement where a 2-of-3 multisig was used with the attorney holding one of the three keys. When the attorney
Multisig quorum failure — 2-of-3 multisig (2015)
Mobile or software wallet
A November 2015 forum case documents a Bitcoin business where three co-founders each held one key of a 2-of-3 multisig treasury. When two of the three co-founde
Multisig quorum failure — exchange 2015
Exchange custody
A Bitcoin startup that used Copay multisig for treasury discovered in March 2015 that one of its three key holders had left the company and wiped their device b
Active escrows were frozen pending a legal challenge to the acquisition.
Exchange custody
A Bitcoin payment escrow service that used 2-of-3 multisig discovered in April 2015 that its third-party key custodian had been acquired by another company. The
The remaining two shareholders could form quorum, but the departed CTO had configured
Exchange custody
A Bitcoin startup that held company treasury in a 2-of-3 multisig discovered that one of its three key holders—a former CTO who had departed acrimoniously—refus
The legal firm dissolved in September 2014.
Mobile or software wallet
A 2014 Bitcoin escrow startup used a 2-of-3 multisig where the third key was managed by a legal firm acting as arbiter. The legal firm dissolved in September 20
AWS retired the specific HSM service used, without the escrow operator having prepared
Exchange custody
A Bitcoin escrow service operating in 2014 used a 2-of-3 multisig where one key was held by an Amazon Web Services HSM. In August 2014 AWS retired the specific
Multisig quorum failure — exchange 2014
Exchange custody
A Bitcoin exchange that had adopted multisig cold storage in early 2014 experienced a quorum failure when one of its three key holders—a contractor—left under d
Multisig quorum failure — Armory (2014)
Mobile or software wallet
An early adopter of Armory's multisig features in 2014 had set up a 2-of-3 arrangement with a friend and an exchange-hosted co-signer. When the exchange-hosted
A 2-of-2 arrangement offered no resilience against single key loss, unlike a 2-of-3
Mobile or software wallet
A Bitcoin business that stored treasury in a 2-of-2 multisig arrangement suffered a key loss when one partner's computer was damaged. The remaining partner held
Multisig quorum failure — exchange 2014
Exchange custody
A Bitcoin startup that implemented a 3-of-5 multisig cold storage arrangement in early 2014 experienced a quorum failure when two key holders simultaneously bec
A 2013 early corporate Bitcoin treasury used a basic 3-of-5 multisig setup.
Exchange custody
A 2013 early corporate Bitcoin treasury used a basic 3-of-5 multisig setup. Two key holders left the company in a dispute and did not disclose their keys. A thi