The cryptographer Dan J. Bernstein once told me a story that Bruce Schneier kept some cryptographic protocol secure for an additional 24 hours. The researcher demonstrating this protocol's weakness based their proof-of-concept on a proof in Schneier's book. However, Schneier's description contained a mathematical error. When the error in the proof-of-concept was pointed out to the researcher at the conference, this researcher went back to their hotel room, discovered the origin of the error in Schneier's text, and fixed the proof-of-concept for the conference-goers by the following day. Thus, Bruce Schneier kept a cryptographic protocol secure for an additional 24 hours.