Outline for October 7, 2022
Reading: text, §10.4–10.5, 11.1–11.2, 12.1
Due: Homework 1, due October 5; Project selection, due Oct 7
- Cryptographic Checksums
- Function y = h(x): easy to compute y given x; computationally infeasible to compute x given y
- Variant: given x and y, computationally infeasible to find a second x′ such that y = h(x′)
- Keyed vs. keyless
- Digital Signatures
- Judge can confirm, to the limits of technology, that claimed signer did sign message
- RSA digital signatures: sign, then encipher, then sign
- El Gamal digital signatures
- Session and interchange keys
- Key Exchange
- Needham-Schroeder and Kerberos
- Public key; man-in-the-middle attacks
- The discrete log problem and Diffie-Hellman
- Attacks
- Precomputation
- Misordered blocks
- Statistical regularities
- Type flaw