RU2032990C1 - Method of encoding of binary information - Google Patents

Abstract

FIELD: cryptographic conversion. SUBSTANCE: given method of encoding of binary information uses n-digit functional conversion. With encoding of due portion of binary information new n-digit functional conversion generated with use of secret key is employed. EFFECT: enhanced reliability of method. 2 cl

Description

 The invention relates to cryptographic transformations and can be used in communication, computing and information systems for cryptographic closure of binary information.

 Known encryption methods for cryptographic protection of information in computer systems and using n-bit functional conversion. These include, for example, the data encryption standard of the US National Bureau of Standards.

 The well-known data encryption standard uses a fixed set of 4-bit functional transformations. These functional transformations are known to everyone and their knowledge, in principle, can be used in the analytical definition of a key by a cryptographic analyst.

 The aim of the present invention is to make the functional transformation used in the method of encrypting binary information unknown to unauthorized persons.

 This goal is achieved by the fact that in the method of encrypting binary information using an n-bit functional transformation, when encrypting the next portion of binary information, a new n-bit functional transformation is used, generated using the cryptographic method of encrypting binary information depending on the secret key.

 If before starting the encryption process using a known key-dependent method of encrypting binary information, to develop a new functional transformation used in the method, this new functional transformation will not be known to outsiders, which will significantly complicate the cryptographic analytics procedure of the analytical calculation of the key used in the encryption method .

An n-bit functional transformation is defined by a table containing 2n cells. If the conversion is one-to-one, then the table cells must be n-bit. A new one-to-one n-bit functional transformation can be developed using the well-known method of encrypting binary information, for example, by the method of dialing n-bit numbers without returning. It is as follows. First, a sequence of pseudorandom bits of sufficient length is generated by a known key-dependent and new, for example random, initial state, method of encrypting binary information. The generated binary sequence is used to set up a table consisting of 2 ^{n of} all possible n-bit numbers. This table defines a one-to-one n-bit function. The first n-bit table number is the first n bits of the generated binary sequence. The second n-bit number of the table is the second n bits of the sequence if they do not match the first n-bit number of the table. If they match, the next n bits of the sequence are taken, and so on, until the next n bits are different from the first number of the table. The third number of the table is the next n bits of the sequence that do not coincide with the first two numbers of the table already dialed. The fourth and subsequent numbers of the table are dialed in the same way, that is, the n-bit group of the sequence not encountered previously is taken as the next number, and n-bit groups that match the earlier dialed numbers of the table are discarded.

 In the process of encrypting binary information, the dialed n-bit functional transformation is used. That is, the functional transformation used in the encryption method is first dialed, and then binary information is encrypted. When decrypting information, you must also first type the table defining the functional transformation. To do this, you need to know the key and initial state used during encryption for the table set.

 Since the key is known only to those who encrypt and decrypt information, the functional transformation typed with its help will be unknown to unauthorized persons.

Claims (3)

 1. BINDER INFORMATION ENCRYPTION METHOD, using an n-bit functional transformation as a component, characterized in that when encrypting the next portion of binary information, a different n-bit functional conversion is used to encrypt the next portion, generated using a secret key-dependent cryptographic encryption method of binary information.  2. The method according to claim 1, characterized in that the next portions of the encrypted information are the next message, separated by time intervals.  3. The method according to claim 1, characterized in that another n-bit functional transformation is generated by the method of repeating a set of n-bit numbers from binary information generated using a cryptographic encryption method that depends on the secret key.