RFC - 1750

Randomness Recommendations for Security

Original:	ftp://ftp.isi.edu/in-notes/rfc1750.txt
Authors:	D. Eastlake, 3rd [DEC], S. Crocker [Cybercash], J. Schiller [MIT]
Date:	December 1994
Category:	Informational
This specification has been !!! obsoleted !!!

---

Obsoleted by:
RFC-4086 [BCP 106]	Randomness Requirements for Security

Referred by:	73 RFC
Refers to:	7 RFC

---

Status

This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Abstract

Security systems today are built on increasingly strong cryptographic algorithms that foil pattern analysis attempts. However, the security of these systems is dependent on generating secret quantities for passwords, cryptographic keys, and similar quantities. The use of pseudo-random processes to generate secret quantities can result in pseudo-security. The sophisticated attacker of these security systems may find it easier to reproduce the environment that produced the secret quantities, searching the resulting small set of possibilities, than to locate the quantities in the whole of the number space.

Choosing random quantities to foil a resourceful and motivated adversary is surprisingly difficult. This paper points out many pitfalls in using traditional pseudo-random number generation techniques for choosing such quantities. It recommends the use of truly random hardware techniques and shows that the existing hardware on many systems can be used for this purpose. It provides suggestions to ameliorate the problem when a hardware solution is not available. And it gives examples of how large such quantities need to be for some particular applications.

Acknowledgements

Comments on this document that have been incorporated were received from (in alphabetic order) the following:

        David M. Balenson (TIS)
        Don Coppersmith (IBM)
        Don T. Davis (consultant)
        Carl Ellison (Stratus)
        Marc Horowitz (MIT)
        Christian Huitema (INRIA)
        Charlie Kaufman (IRIS)
        Steve Kent (BBN)
        Hal Murray (DEC)
        Neil Haller (Bellcore)
        Richard Pitkin (DEC)
        Tim Redmond (TIS)
        Doug Tygar (CMU)

---