By 2017 they could not fully reconstruct the algorithm from memory.

Blocked

Case description

A software engineer used a self-written key-stretching algorithm to generate a wallet passphrase in 2013. By 2017 they could not fully reconstruct the algorithm from memory. They retained notes describing parts of it, but the precise sequence of operations was ambiguous.

Custody context

Stress condition	Passphrase unavailable
Custody system	Mobile or software wallet
Outcome	Blocked
Documentation	Unknown
Year observed	2017
Country	Unknown

Structural dependencies observed

Single point of failure

What this illustrates

The seed phrase was there, but the passphrase that unlocked it was gone. Both are required. Access was not recoverable.

Outcome interpretation

Access was not possible under the reported conditions.

Source

Publicly Reported

Evidence type

Forum post

Evidence link

https://bitcointalk.org/index.php?topic=255793.0

Related cases involving passphrase unavailable

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This archive documents observed custody survivability failures. It does not attempt to document all Bitcoin losses or security incidents. Submit a case

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Framework references

Where Bitcoin Custody Intersects Legal and Fiduciary Authority

Where custody creates gaps in estate planning, fiduciary duty, and professional responsibility.

Professional Scope Boundary Matrix

What each professional or product covers, what they do not, and where gaps form between them.

The Independent Assessment Layer in Bitcoin Custody

How independent diagnostic layers emerge when multiple parties depend on shared infrastructure.