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The Copiale cipher is a substitution cipher. It is not a 1-for-1 substitution but rather a homophonic cipher: each ciphertext character stands for a particular plaintext character, but several ciphertext characters may encode the same plaintext character. For example, all the unaccented Roman characters encode a space.
Manifold stylographic writer, using early "carbonic paper" Letter copying book process; Mechanical processes Tracing to make accurate hand-drawn copies; Pantograph, manual device for making drawn copies without tracing, can also enlarge or reduce; Printmaking, which includes engraving and etching. Relief printing including woodcut
Folio 13 of the Cipher MMS. The cipher used in the manuscripts, shown in a 1561 edition of Trithemius' Polygraphia. Another cipher known as "Theban" is given above it. The folios are drawn in black ink on cotton paper watermarked 1809. [1] The text is plain English written from right to left in a simple substitution cryptogram. Numerals are ...
A secret decoder ring (or secret decoder) is a device that allows one to decode a simple substitution cipher—or to encrypt a message by working in the opposite direction. [ 1 ] As inexpensive toys, secret decoders have often been used as promotional items by retailers, as well as radio and television programs, from the 1930s through to the ...
The paper serves as the foundation of secret-key cryptography, including the work of Horst Feistel, the Data Encryption Standard (DES), Advanced Encryption Standard (AES), and more. [5] In the paper, Shannon defined unicity distance , and the principles of confusion and diffusion , which are key to a secure cipher.
In the history of cryptography, a grille cipher was a technique for encrypting a plaintext by writing it onto a sheet of paper through a pierced sheet (of paper or cardboard or similar). The earliest known description is due to Jacopo Silvestri in 1526. [ 1 ]
Gilbert Sandford Vernam (April 3, 1890 – February 7, 1960) was a Worcester Polytechnic Institute 1914 graduate and AT&T Bell Labs engineer who, in 1917, invented an additive polyalphabetic stream cipher and later co-invented an automated one-time pad cipher.
On the right is the paper tape transport mechanism that was dubbed the "bedstead" because of a resemblance to an upended metal bed-frame. [ 1 ] Heath Robinson was a machine used by British codebreakers at the Government Code and Cypher School (GC&CS) at Bletchley Park during World War II in cryptanalysis of the Lorenz cipher .