On Sun, 26 Jan 2003, Matt Blaze wrote: > The tragic part is that there are alternatives. There are several > lock designs that turn out to resist this threat, including master > rings and bicentric locks. While these designs aren't perfect, they
I think it is worth pointing out that, while master ring systems (and master-keyed systems with false steps added) resist the attack Matt describes, they often make the task of picking the lock (on a case by case basis) easier. That needs to be considered when designing a physical security plan. One may wish to key locks of particular importance separately from the master ring system if entry by picking is a concern. (There are some master-key systems, like the one made by Corbin, that require pin rotation at the proper time to unlock the secondary sheer line. And, as Matt mentioned, bicentric cylinders avoid this problem completely. Cost may be a major concern with these solutions, though.) --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]