Search results
Results from the WOW.Com Content Network
Hill's cipher machine, from figure 4 of the patent. In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra.Invented by Lester S. Hill in 1929, it was the first polygraphic cipher in which it was practical (though barely) to operate on more than three symbols at once.
In cryptography, unicity distance is the length of an original ciphertext needed to break the cipher by reducing the number of possible spurious keys to zero in a brute force attack. That is, after trying every possible key , there should be just one decipherment that makes sense, i.e. expected amount of ciphertext needed to determine the key ...
The Massey–Omura method uses exponentiation in the Galois field GF(2 n) as both the encryption and decryption functions. That is E(e,m)=m e and D(d,m)=m d where the calculations are carried out in the Galois field. For any encryption exponent e with 0<e<2 n-1 and gcd(e,2 n-1)=1 the corresponding decryption exponent is d such that de ≡ 1 ...
Lester S. Hill (1891–1961) was an American mathematician and educator who was interested in applications of mathematics to communications.He received a bachelor's degree (1911) and a master's degree (1913) from Columbia College and a Ph.D. from Yale University (1926).
Bob generates 2 N messages containing, "This is message X. This is the symmetrical key Y", where X is a randomly generated identifier, and Y is a randomly generated secret key meant for symmetrical encryption. Hence, both X and Y are unique to each message.
The difficulty or impossibility of solving certain geometric problems like trisection of an angle using ruler and compass only is the basis for the various protocols in geometric cryptography. This field of study was suggested by Mike Burmester, Ronald L. Rivest and Adi Shamir in 1996. [ 1 ]
The motivation for this problem is that many security systems use one-way functions: mathematical operations that are fast to compute, but hard to reverse. For example, they enable encrypting a message, but reversing the encryption is difficult. If solving the DHP were easy, these systems would be easily broken.
The concept of public key cryptography was introduced by Whitfield Diffie and Martin Hellman in 1976. [3] At that time they proposed the general concept of a "trap-door one-way function", a function whose inverse is computationally infeasible to calculate without some secret "trap-door information"; but they had not yet found a practical example of such a function.