Using unpredictable information to Resist Discovery of Secrets by External Monitoring

• Main Authors: Kocher, Paul C, Jun, Benjamin C, Jaffe, Joshua M
• Format: Patent
• Language: English; French; German
• Published: 02.05.2018
• Subjects: CALCULATING; CHECKING-DEVICES; COIN-FREED OR LIKE APPARATUS; COMPUTING; COUNTING; DATA PROCESSING SYSTEMS OR METHODS, SPECIALLY ADAPTED FORADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL, SUPERVISORYOR FORECASTING PURPOSES; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; HANDLING RECORD CARRIERS; JAMMING OF COMMUNICATION; PHYSICS; PRESENTATION OF DATA; RECOGNITION OF DATA; RECORD CARRIERS; SECRET COMMUNICATION; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE,COMMERCIAL, FINANCIAL, MANAGERIAL, SUPERVISORY OR FORECASTINGPURPOSES, NOT OTHERWISE PROVIDED FOR; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

A method of and cryptographic processing device for securely performing a cryptographic processing operation implementing a permutation in a manner resistant to discovery of a secret within a cryptographic processing device by external monitoring, operates by receiving a quantity to be cryptographically processed; generating unpredictable information; using the unpredictable information while processing the quantity to conceal a correlation between externally monitorable signals and the secret, this being achieved by performing a computation and incorporating the result of the computation in the cryptographic processing, and performing a computation the output of which is not incorporated in the cryptographic processing; and outputting the cryptographically processed quantity to a recipient thereof. The unpredictable information thus conceals a correlation between externally monitorable signals and the secret by randomizing the order of the permutation.