Best practice for periodic key change?

[David Shaw]

On May 7, 2011, at 11:04 PM, Jerome Baum wrote:

> On Sun, May 8, 2011 at 04:53, David Shaw <dshaw at jabberwocky.com> wrote:
> I knew a man (a lawyer, as it happened) who always signed documents with several loops in a row.  When I asked him why he didn't use a "real" signature (i.e. why he didn't sign his name), he just grinned and said "Who's to say this isn't my signature?"   My own signature is sufficiently unreadable that it could safely be described as a "mark".
> 
> Speaking of which, there was this article recently on how people aren't learning cursive writing anymore and this makes (physical) signature verification more difficult. My signature is a semi-readable cursive "Jerome Baum" (read: "Jer~~~ B~~~" ;) ) so I should be safe, but I'm wondering how secure it actually is? Anybody know a good article on physical signature security? I know the analyses are all about writing speed and pressure but it would be good to see this "dumbed down" for casual reading.

I bookmarked this at one point: www.thomasgroganfde.com/pdf/Article_Protect_Identity.pdf

He gives a few recommendations (cross your own lines frequently, consistency is important, think about using a different signature for legal matters vs correspondence, etc).  How good the advice is I couldn't say, but I found it and some other documents on the site interesting reading.

David