Résumé: If <GAMMA><subscript>p is a p-ary code of length n, and a and b are two codewords, then c is called a descendant of a and b if c<subscript>i <Element of> {a<subscript>i, b<subscript>i } for i = 1,..., n. We are interested in codes <GAMMA><subscript>p with the property that for any two codewords a and b their only descendant codewords are a and b themselves. This way a coalition of two users who are given codewords a and b cannot frame a third user who is given the codeword c. Intersecting codes over primary field GF( p) with the above mentioned property are found.

Langue: Anglais