From: Wayne Godbehere (1/18/96) Date: Thu, 18 Jan 1996 07:02:04 -0500 To: infosec@mitre.org From: "Wayne Godbehere" (by way of woycke@mitre.org (Daniel W. Woycke)) Subject: FYI: Exportable 64 bit encryption announced Today at the RSA conference IBM/Lotus announced that they have Commerce approval to ship a "differential work factor reduction" 64 bit encryption. It will be part of their Lotus Release 4 which is shipping now. It will operate as follows: it will use 64 bit which will be what would need to be compromised by interlopers; however, 24 bits will be bound to 40 bits... the 24 bits are encrypted with a Government public key, effectively leaving the key length not know to the government remains at 40 bit. This is a compromise solution to offer strong encryption to overseas clients while meeting Commerce department limitations. It is an interim measure until the expected easing of export restrictions. This solution will be flexible and scales to any key/escrow requirements. For example, if 80 bit keys become the vogue, then 40 bits would be encrypted with the government public key rather than 24, thereby leaving 40 bits unknown to government watchers. This type of approach should be implementable and exportable by other products. ============================================================== | Public Key Infrastructures Wayne W. Godbehere | - an architecture for Director - Secure Services | privacy, integrity, and Bell Sygma Systems Management | authentication Toronto, Ontario | Ph: 416-285-9968 x.224 ============================================================== Opinions expressed do not necessarily reflect those of my employers or co-workers. ====================================================================== From: schaen@smiley.mitre.org (Sam Schaen) Subject: Re: Easing of Export Controls on Encryption Software >In yesterday's New York Times (15 January 1996), there was a brief article >that stated that the Commerce Department will recommend easing export >controls on encryption software. The article points to a study by the >Commerce Department and NSA that found that American companies are being >hurt and that U.S. companies are at a "tremendous competitive >disadvantage." > > -Brian At the RSA conference today, Lotus announced a feature in Notes 4.0 that allows 64 bit RC4 keys using a technique called differential work factor to be exported. In that technique, 24 bits are encrypted in a US govt public key so that the govt can break the code with a work factor equivalent to a 40 bit key, but other attackers face a 64 bit key. The technique has been approved and is currently shipping. It is a possible compromise solution that addresses some of the recent criticism of breakable encryption. It will be interesting to see if the solution is acceptable abroad. It will also be interesting to see if further relaxation is permitted. For example, Whitfield Diffie commented that he would have preferred to see a 48 bit rather than 40 bit workfactor for the government. -Sam