Dig. Cash Question.

[J. Michael Diehl]

I'm reading the paper that was announced on this list about Digital Cash last 
week.  It was writen by Stefan Brands.  I think I have a strong Math background,
but I don't know what is meant by a "descrete log" in a group G.  I understand
what a group is.  I just don't know what properties an element, a, would have
if it were the log sub p of e.  Can someone help me.  Otherwise, this is a
very interesting article.  Thanx in advance.
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