John Young writes:
Along this line:
A few days ago we received an 8-page excerpt from "Shift Register Sequences," by Solomon W. Golomb (at USC), Holden-Day, Inc., no date, with a handwritten note:
NSA has tried to suppress knowledge of this stuff. Nearly all NSA 'good' algorithms are based on this technology.
IANAM, so would any of the mathematicians here give any credibility to this claim?
"The Magic Singing and Dancing Shift Register Algorithm" has been making the rounds for a number of years now, and surfaces in various forms at periodic intervals on the Net. It is based on a mathematical technique once used to do transcendental function approximation on now slow and obsolete calculator chips, and as far as I can tell, offers no magic insights into efficient ways of computing cryptographically interesting functions, such as factoring, descrete log, or symmetric block cipher key recovery. I would put it in my comedy file along with the "RSA is Easy To Break" paper, and similarly innumerate rants.
We'll scan and put the excerpt on our Web site if worthwhile. It's composed of the book's 3 page preface and 5 pages of text and diagrams of Chapter 2 on The Shift Register as a Finite State Machine, with principal focus on de Bruijn diagrams for shift registers.
The book is probably a serious text on the mathematical techniques in question. But unless you are looking for a way to compute Trig functions with lots of iterations and little hardware, it probably isn't worth more than a cursory glance. It's not going to break codes for you. -- Mike Duvos $ PGP 2.6 Public Key available $ enoch@zipcon.com $ via Finger $ {Free Cypherpunk Political Prisoner Jim Bell}