"...
Cryptology became almost entirely a technology, an
applied science in the
service of
power ...even though
cryptanalysis is quintessentially statistical,
cryptology did not take any steps of importance toward quantification until
William
F. Friedman in 1920 matched
frequency distribution to reconstruct a
plaintext
alphabet in his groundbreaking
The index of coincidence and its applications in
cryptography (Geneva, Ill. :
Riverbank Laboratories, 1922). -from
David Kuhn, "The
Grand Lines of Cryptology's development",
Computers and Security , Nov.
1982.
Precursors of this text, however, for all the
cypherpunk history geeks out there, also
included
Leon Baltista Albertiæ, who in 1466 adapted a disk device, which when turned in various combinations, generated an exhaustive list of arguments to
convert Muslims (essentially the first
disk
polyalphabetic substitution cipher , using
polyalphabetic substitution ).
Alberti's contemporary
Johannes Trithemius (1462-1516) was at the same time mingling
cryptographic
methods with
angelic script in his
treatise Steganographia, hoc est, Ars per
occultam scripturam animi sui voluntatem absentibus aperiendi certa (Frankfurt :
1608), which while only clocking in at 70 p. is still one of the earliest European works
on the subject of
invisible writing and practical
cryptography .
Œ
æAlbertis' treatise was entitled
De Cifris, was 26p., and outlined the use of two interlocked rings, forming a
disk, which could be rotated to produce different correspondences between opposed rings of letters- which may have been inspired by the Islamic
astrolabe introduced to Europe the century beforehand, following the last
Crusades.
Œ And should you be curious, and in the Montreal area, stop by
McGill University , and if you can find the Rare Books room, then you can have a
look for yourself . . .but bring photo ID.