2003/02/04 by Klein, Andreas, Wessler, Markus
#Combinatorics (math.CO) #FOS: Computer and information sciences #FOS: Mathematics #Information Theory (cs.IT)
paper · doi:10.48550/arxiv.math/0302043
Visual cryptography schemes have been introduced in 1994 by Naor and Shamir. Their idea was to encode a secret image into n shadow images and to give exactly one such shadow image to each member of a group P of n persons. Whereas most work in recent years has been done concerning the problem of qualified and forbidden subsets of P or the question of contrast optimizing, in this paper we study extended visual cryptography schemes, i.e. shared secret systems where any subset of P shares its own secret.