Chaum's patents

[Hal]

s1018954 at aix2.uottawa.ca writes:

>Sorry if this has been stated before, but exactly when do Chaum's first
>set up e-cash related patents expire? I looked it up in applied crypto
>the last time I had my hands on it and couldn't find the dates. 

>How many (and what) patents are there in this field anyway? (don't bother 
>with that if it's too long to answer)

I did a patent search a few months ago, with results at <URL:
http://www.portal.com/~hfinney/chaum_patents.html>.  Chaum has several
patents; my lists doesn't have all of them.  The ones I have are dated
1988 and 1990.

Hal