Polybius was responsible for a useful tool in telegraphy that allowed letters to be easily signaled using a numerical system (mentioned in Hist. X.45.6 ff.). This idea also lends itself to cryptographic manipulation and steganography.
This was known as the "Polybius square", where the letters of the alphabet were arranged left to right, top to bottom in a 5 x 5 square, (when used with the modern 26 letter alphabet, the letters "I" and "J" are combined). Five numbers were then aligned on the outside top of the square, and five numbers on the left side of the square vertically. Usually these numbers were arranged 1 through 5. By cross-referencing the two numbers along the grid of the square, a letter could be deduced.
In the The Histories, he specifies how this cypher could be used in fire signals, where long-range messages could be sent by means of torches raised and lowered to signify the column and row of each letter. This was a great leap forward from previous fire signaling, which could send prearranged codes only (such as, 'if we light the fire, it means that the enemy has arrived').
Other writings of scientific interest include detailed discussions of the machines Archimedes created for the defense of Syracuse against the Romans, where he praises the 'old man' and his engineering in the highest terms, and an analysis of the usefulness of astronomy to generals (both in the Histories).
Read more about this topic: Polybius
Other articles related to "cryptography":
... Cryptography is central to digital rights management (DRM), a group of techniques for technologically controlling use of copyrighted material, being ... This had a noticeable impact on the cryptography research community since an argument can be made that any cryptanalytic research violated, or might violate, the DMCA ... Niels Ferguson, a well-respected cryptography researcher, has publicly stated that he will not release some of his research into an Intel security ...
... Cryptography Research, Inc. ... is a San Francisco based cryptography company specializing in applied cryptographic engineering, including technologies for building tamper-resistant ... Cryptography Research protects its core operations from outside attack by maintaining a secured local network that is not connected to the Internet at all ...
... für Daten im ISDN B-Kanal" (German, meaning, "Implementation of Cryptography for Data contained in the ISDN Bearer channel"), at the Technische Fachhochschule Berlin ... For the cryptography Floricic used cheap DSPs from Texas Instruments which he scrapped out of old computer modems, but which could also be bought at ... As this type of DSP is not powerful enough for the cryptography algorithm chosen, Floricic used two of them for the Cryptophon – one for sending and one for receiving ...
... einer Verschlüsselungstechnik für Daten im ISDN B-Kanal" (German, meaning, "Implementation of Cryptography for Data contained in the ISDN Bearer channel"), at the Technische ... For the cryptography Floricic used cheap DSPs from Texas Instruments which he scrapped out of old computer modems, but which could also be bought at affordable prices ... As this type of DSP is not powerful enough for the cryptography algorithm chosen, Floricic used two of them for the Cryptophon – one for sending and one for receiving ...
... of various fields such as number theory, and more recently in cryptography and Digital Signature Authentication (See elliptic curve cryptography and elliptic curve DSA) ... consequences in the solving of Diophantine equations, with respect to cryptography, they enable us to make effective use of the difficulty of the discrete ... known, is a widely used approach to Public key cryptography, and the difficulty in solving this problem determines the level of security of the cryptosystem ...