Computing methods and the phase problem in X-ray crystal by Ray, editor Pepinsky

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This makes it necessary to provide a comprehensive range of possible protection tools and functions. It makes the most sense to first protect the most informative channels of data leakage, such as: the possibility of quickly and easily copying data onto removable high-capacity media, unsecure communication channels, and the theft of a hard drive or a whole computer. The problem of barring these leakage channels is complicated by the requirement that data protection procedures shouldn't lead to a noticeable decrease in the performance of the CS.

There were a number of successful attacks on the DES, RC5, and Blowfish cryptosystems when a small number of enciphering rounds was used. Obviously, one can choose a size of a random block R that will make reduced versions of these ciphers secure against known attacks. For this purpose, the r = b − 1 value will do. Ciphers with a simple probabilistic mechanism have the following advantages: ♦ The security of the known block ciphers can be significantly increased. ♦ In a sense, it is possible to control the cipher's security by choosing various values for the r/b ratio.

During probabilistic encryption, for the given text T, we generate one of the possible cryptograms — for example, Ci, chosen from the {C1, C2, …, CN} set according to the probabilistic law. A cryptanalyst can correctly choose the original text, but he or she cannot verify this fact, since, when encrypting, he or she will generally obtain another cryptogram from the set of possible variants. Having encrypted T, the cryptanalyst will get Cj = Ez(T). The probability that Cj = Ci is 1/N. The cryptanalyst has to guess not only the original text, but also the value of a randomly selected parameter that controls the probabilistic encryption process.