Keep it secret, stupid!

[Len Sassaman]

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.)



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