Exploiting Key Space Vulnerabilities in the Physical World (Q&A)
Bill Graydon answers questions regarding lock impressioning mathematics, key space entropy, and physical master key auditing.
Summary
In this technical Q&A session from the DEF CON Safe Mode Main Stage, physical security researcher Bill Graydon explores algorithmic key space reduction techniques in mechanical locking systems. Opening at 00:14, Bill addresses community questions regarding how commercial lock manufacturers historically treated key bitting specifications and manufacturing tolerances as proprietary secrets.
At 07:02 and 14:02, Bill details the mathematical framework behind physical key space reduction, explaining how penetration testers use constraint satisfaction algorithms to eliminate impossible pin combinations and dramatically shrink the search space required to decode master-keyed systems.
Concluding at 21:01 and 28:01, Bill demonstrates applying these probabilistic methodologies across pin-tumbler cylinders and mechanical combination locks, providing actionable guidance for facility managers to audit and harden master key architectures against unauthorized duplication. (AI summary — Gemini Flash)
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