METHOD OF TRANSMITTING DISCRETE MESSAGES SECURE FROM UNAUTHORISED ACCESS Russian patent published in 2011 - IPC H04L9/18 H04L1/16 

FIELD: information technology.

SUBSTANCE: method of transmitting discrete messages secure from unauthorised access involves dividing an input signal into blocks with length of n bits, creating a discrete message α in form of a sequence of N blocks, creating a copy of the discrete message β by coding the discrete message through modulo P=2ⁿ addition of each block α_i where i=1…N, with a block β_i-1 in accordance with the expression β_i=β_i-1+α_i(mod P) and transmission thereof to a communication line, characterised by that blocks of the created discrete message and its copy totaling no more than N/2 are distorted, selected in accordance with a random law while satisfying the following conditions: block α_i may be distorted if i≠N and blocks α_i-1, α_i+1 β_i, β_i+1, β_i-1 are not distorted; block β_i may be distorted if i≠N and blocks α_i, α_i+1, α_i-1, β_i+1, β_i-1 are not distorted. Distortion of a block is performed by inverting not less than one bit of that block. At the receiving end of the communication line for each block α_i of the discrete message and the corresponding block β_i of the copy of the discrete message, the following identical equations are checked for truth: βi =α_i + β_i-1(mod P), (1); β_i+1 =α_i+1 + β_i(mod P), (2); β_i+1 =α_i+1+ α_i+ β_i-1(mod P), (3) if identical equation (2) is true and identical equations (1) and (3) are false, the block α_i is restored using the formula α_i=β_i+β*_i-1(mod P), where β*_i-1=P-β_i-1, if equation (3) is true and equations (1) and (2) are false, the block β_i is restored using the formula β_i=β_i+β_i-1(mod P), if equation (1) is true and equations (2) and (3) are false, the (i+1)-th block is then restored.

EFFECT: high security of information transmitted over a communication line.

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