Irdeto Corporate B.v.

Irdeto B.v.

Koninklijke Philips Electronics N.v.

Wilhelmus P A J Michiels

Paulus M H M A Gorissen

Aweke Negash Lemma

Mehmet Utku Celik

Ludovicus M G M Tolhuizen

Hendrik D L Hollmann

Stefan Katzenbeisser

Aweke N Lemma

A cryptographic system comprises a white-box implementation of a function; an implementation of a cryptographic algorithm; and an implementation of a combining operation for establishing cryptographically processed data in dependence on an outcome of the function and in dependence on an outcome of the cryptographic algorithm. The combining operation comprises combining an outcome of the cryptographic algorithm with an outcome of the function. Alternatively, the combining operation comprises combining an outcome of the function with a received data element to obtain a combination outcome and applying the cryptographic algorithm to the combination outcome.

Cryptographic system

A system for cryptographic processing of content comprises an input for receiving the content. A plurality of look-up tables represents a white-box implementation of a combined cryptographic and watermarking operation. The look-up tables represent processing steps of the combined cryptographic and watermarking operation and the look-up tables being arranged for being applied according to a predetermined look-up scheme. The look-up scheme prescribes that an output of a first look-up table of the plurality of look-up tables be used to generate an input of a second look-up table of the plurality of look-up tables. The combined cryptographic and watermarking operation comprises a cryptographic operation and a watermarking operation. A control module looks up values in the plurality of look-up tables in dependence on the received content and in accordance to the look-up scheme, thereby applying the combined cryptographic and watermarking operation to the content.

Cryptographic processing of content

A method of creating an encryption system for encrypting a plurality of plaintext words is provided. The method comprises associating () respective plaintext words () with respective sets () of error positions () of an error vector, and associating () respective values of at least one of the plaintext words () with respective error vector values, wherein positions of the respective error vector values outside the set () of error positions associated with the one of the plaintext words () are zero. The method further comprises associating () the respective values of the plaintext word () with respective representations of respective syndromes () of the respective error vectors according to an error correcting code.

A system for enabling a device to compute an outcome of an exponentiation Chaving a base C and/or an exponent x, the system comprising means for establishing a plurality of values &#x3bb;; means for establishing a plurality of values &#x3c9;satisfying &#x3c9;=C; means for establishing a plurality of values &#x3c6;satisfying that the sum of the values &#x3bb;&#x3c6;equals x; and an output for providing the device with the plurality of values &#x3c6;. A device computes an outcome of the exponentiation C. The device comprises means for computing a product of the values &#x3c9;to the power of &#x3c6;. The device is arranged for using the product as a result of the exponentiation C.

White-box implementation

A method of obfuscating an exponent is provided. The method comprises identifying a value &#x3bb; for which it holds that &#x3bb;&#x3e;0 and x=1 for a plurality of elements x which are to be used in a cryptographic process. The method further comprises identifying an obfuscated exponent y which is greater than &#x3bb; and providing information indicative of the obfuscated exponent y. The method comprises establishing a key value a, wherein a&#x3c;&#x3bb;, selecting a positive integer b, and computing y=a+b&#x3bb;.

Growing community of inventors

Eindhoven, Netherlands

Wilhelmus P A J Michiels