SECRET UNITED STATES GOVERNMENT MEMORANDUM Serial: EQ-010-93 DATE: 20 January 1993 REPLY TO ATTN OF: XXXXXX NAME WITHHELD PER NSA XXXXXXXXX SUBJECT: Outside Crypto-mathematicians to Examine CLIPPER - DECISION MEMORANDUM TO: Director THRU: D/DIR____, ExDIR_____ 1. Assuming that there will be vocal public doubts expressed about having a classified algorithm in the device we propose for the U.S. law enforcement problem, the CLIPPER chip, we recommend the following to address this: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX PARAGRAPH 2 BLACKED OUT XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX AS STILL SECRET PER NSA XXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 3. If such people agree to this clearance and non-disclosure process, we could go over the algorithm with them to let them develop confidence in its security, and we could also let them examine the detail design of the CLIPPER chip made for the U.S. law enforcement problem to assure themselves that there were no trapdoors or other techniques built in. This would likely require crypto-mathematicians for the algorithm examination and microelectronics chip design engineers for the chip examination. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXX LINES BLACKED OUT AS STILL SECRET XXXXXXXXXXXXXX XXXXXXXXXXXXXX PER NSA XXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX CLINTON C. BROOKS XXXXX LINE BLACKED OUT PER NSA XXXXXX Decision: ___ Agree with this approach ___ Want to hear thoughts of others on Distribution ___ Let's discuss OPTIONAL FORM NO 10 (REV. 1-80) GSA FPMR (41 CFR) 101-11.6 CLASSIFIED BY NSA/CSSM 193-2 SECRET