FIELD: checking integrity of accumulated data during item processing. SUBSTANCE: method involves entering sound data in memory of check-up device which correspond corresponding to data being checked and held in sound condition in plant component used for processing in definite mode of operation of this plant. Key is generated in checking device for each check procedure to inspect data being checked for integrity. Two cryptograms are formed by means of this key and cryptographic algorithm. One cryptogram is formed from data stored in data processing component and subject to checking by the latter. Other cryptogram is formed by checking device from sound data. After that both cryptograms are compared; if they are consistent, data being checked are also considered to correspond to sound data, and hence they have no unwanted changes. EFFECT: provision for checking data for integrity to reveal their changes. 18 cl, 9 dwg
