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Digital signatures
Merkle, Diffie, Hellman

Is there a functional equivalent to a handwritten signature for a digital document?

Should be:



Definition A digital signature scheme consists of:

Example (RSA)

A user A chooses a pair of primes p,q, and publishes n=pq, keeping p and q secret. He also chooses d with gcd(d,phi(n))=1, and computes e with ed=1 (mod phi(n)). He then publishes e and keeps d secret. Take M =S =Z/nZ, and define

Note that e and n are public, so anyone can compute VA, but we hope that only A can compute SA.


In practice, we replace m by h(m) where h is a strongly collision free function.



Kevin McCurley
1/23/1998