Introduction to Cryptography with Open-Source Software

Chapter 14

Advance d appli cations and protocols

Previous chapters have been c oncerned with the basic building blocks of cryp-

tography: information integrity and authenticity, digital signatures, hash

functions and their uses, a nd the associa ted mathematics and a lgorithms.

This chapter shows how those building blocks ca n be used for more advanced

purposes. In particular:

1. Secure multi-party communica tion, where different parties collude to

create a shared result, with each party keeping its input secr e t from the

others.

2. Zer o knowledge proofs, where a “prover” must provide a proof of some

knowledge to a “verifier,” but without actually giving ...