Exploiting Key Space Vulnerabilities in the Physical World
Bill Graydon applies information theory to physical master key systems, demonstrating how to mathematically reconstruct building master keys from partial key impressions.
Summary
Information Theory in Physical Master Key Systems
Pin-tumbler master key systems rely on geometric key bittings to balance user access, but mathematical relationships between keys leak entropy about the system architecture.
Applying Entropy and Key Space Cryptanalysis
Bill Graydon demonstrates how comparing just a few employee office keys allows calculating the exact bitting parameters of the building master key without picking a single lock.
Impressioning and Decoding Pin Stacks
Combining physical lock impressioning techniques with information-theoretic reduction algorithms drastically reduces the search space needed to cut a functional master key.
Designing Secure Master Key Hierarchies
Graydon presents defensive key management guidelines and mathematical validation models for locksmiths and physical security engineers to eliminate key space leakage.
Related talks
Main Stage·1 hr 46 min
Bill Graydon
Bill Graydon demonstrates applying information theory and entropy reduction to derive physical building master keys from partial impressions.
Main Stage·28 min
Bill Graydon
Bill Graydon answers questions regarding lock impressioning mathematics, key space entropy, and physical master key auditing.
Lock Picking Village·27 min
Austin Marck
Explores master key system architecture, key bitting matrices, and progression attacks to decode entire facility master keys.