Device for transforming a digital data sequence into a condensed digital data block using tables and logic operators

An electronic device for processing digital data, the device comprising:

• an input for receiving data to be processed;
• and
• processor means for transforming input data in a non-falsifiable manner into a result condensed data block;
• wherein the processor means comprise:
• means for breaking the input data into at least a first group comprising M first input words with respective ranks I lying in a range from 1 to M each of the first input words having a same number B of elementary data items, and a second group comprising M second input words of respective ranks I lying in the range 1 to M, each of the second input words having the same number B of elementary data items;
• first means forming a first array having entries of sizes M and V where V is a predetermined value representing an upper limit of a processing index K, contents of cells in the first array having integer values lying in a range 1 to 2M;
• second means forming a second array having entries of respective sizes M and V, the second array having cells whose contents take integer values lying in the range 1 to 2M;
• third means forming a third array having entries of respective sizes V and M, the third array having cells containing integer values lying in a range 1 to 2.sup.B to define an auxiliary table of V.M auxiliary words;
• and
• a composite operator for providing a special function having entries of the same size B, thereby performing an EXCLUSIVE OR operation on the entries followed by a non-linear permutation on a result of said EXCLUSIVE OR operation;
• and wherein the processor means are operable for:
• a) initializing the processing index K to 1;
• b) establishing an initial value of a current intermediate word at rank I equal to 1;
• c) initializing the rank I to 2;
• d) replacing the input word of the first group of rank I with the input word whose group and rank are defined by the contents of a cell in the first array whose entry address of size M is equal to the rank I, thus obtaining a first substitute word;
• e) replacing the input word of the second group of rank I by the input word whose group and rank are defined by the contents of a cell of the second array whose entry address of size M is equal to the rank I, thereby obtaining a second substitute word;
• f) applying the second substitute word and an auxiliary word contained in a cell of the auxiliary table whose entry address of size M has a value equal to the rank I to respective entries of the composite operator, thereby obtaining a first term word;
• g) applying the first substitute word and the first term word to respective entries of the composite operator, thereby obtaining a second term word;
• h) applying the current intermediate word and the second term word to respective entries of the composite operator, thereby obtaining a new current intermediate word;
• i) repeating operations d) to h) selectively, and for each repetition incrementing the rank I until the value M is reached, thereby obtaining a result word of B elementary data items for a processing index of value K;
• j) selectively repeating operations b) to i), and for each repetition incrementing the processing index until reaching an upper limit, thereby obtaining a result condensed data block of V result words each comprising B elementary data items.