Appendix A: Changes from RFC 1750

1. Additional acknowledgements have been added.

2. Insertion of section 5.3 on mixing with S-boxes.

3. Addition of section 3.3 on Ring Oscillator randomness sources.

4. Addition of AES and the members of the SHA series producing more than 160 bits. Use of AES has been emphasized and the use of DES de-emphasized.

5. Addition of section 6.3 on entropy pool techniques.

6. Addition of section 7.2.3 on the pseudo-random number generation techniques given in FIPS 186-2 (with Change Notice 1), 7.2.1 on those given in X9.82, section 7.1.2 on the random number generation techniques of the /dev/random device in Linux and other UNIX systems, and section 7.1.3 on random number generation techniques in the Windows operating system.

7. Addition of references to the "Minimal Key Lengths for Symmetric Ciphers to Provide Adequate Commercial Security" study published in January 1996 [KeyStudy] and to [RFC1948].

8. Added caveats to using Diffie-Hellman as a mixing function and, because of those caveats and its computationally intensive nature, recommend against its use.

9. Addition of references to the X9.82 effort and the [TURBID] and [NASLUND] papers.

10. Addition of discussion of min-entropy and Renyi entropy and references to the [LUBY] book.

11. Major restructuring, minor wording changes, and a variety of reference updates.