[4081] in cryptography@c2.net mail archive
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daemon@ATHENA.MIT.EDU (MCKAY john)
Thu Jan 28 12:28:46 1999
To: cryptography@c2.net
Date: Thu, 28 Jan 1999 11:06:34 -0500
From: MCKAY john <mckay@cs.concordia.ca>
This I got from computer historian, Simon Lavington.
The (Manchester) Ferranti Mark I had a hardware random number generator.
This was specified by Alan Turing - (A copy of his original
Internal Report, dated 1949 I believe, still exists.) The random
number instruction was based on electron noise in a thermionic
diode. Turing's report even gives a possible circuit diagram.
The same strategy is used today in the UK Dept. of National
Savings' ERNIE Premium Bond machine.
Another curiosity of the Mark I's instruction set was a sideways
add ('population count'), also specified by Turing. I've always
assumed that the two instructions could be useful for cryptography -
eg for the generation of one-time coding pads and the testing of
decryption procedures.
