Bogus digital signatures, Re: OT: utility account transfer frauds

[John R T Brazier]

David Swarbrick stated:
> Does anyone yet have a workable protocol for sighning documents?

BTW, completely agree with your comments! It depends on what you mean by
"workable", but here's some refs.

Scheier Applied Crypto Ed 2 on p 40 gives a signing protocol that attempts
to avoid repudiation (from S G Akl, "Digital Signatures: A Tutorial Survey",
Computer, v16, No2, Feb 1983 pp 15-24). It need a verifier and and
timestamps. He gives two other refs:
K S Booth "Authentication of Signatures Using Public Key Encryption", Comms
of the ACM, v21 No 11, Nov 1981
R DeMillo & M Merritt "Protocols for Data Security", Computer v16 No2,
Feb1983.

In Crypto 97 there's a paper by R Gennario, H Krawczyk & Tal Rabin on
"RSA-Based Undeniable Signatures" (pp132-149), which has a whole barrel-load
of references.

Chapter 11 in Menezes et al's "Hanbook of Applied Cryptography" Chapter 11
is a bright and breezy read.

All the best,

John B
--
David Swarbrıck  david@swarb.freeuk.com
david.swarbrick@lawindexpro.co.uk