METHOD FOR CONTROLLING VALIDITY OF AN ATTRIBUTE

A device comprises a hash tree including a root node and a leaf node. An issuing authority having agreed to generate a signature of the root node after having successfully checked validity of an attribute stored in the leaf node. The device identifies a subset of nodes by using a template specifying the structure of the hash tree, said subset comprising, for all paths of the hash tree that do not comprise said leaf node, the node which is the closest to the reference root node and which does not belong to the path comprising said leaf node. A verifier computes a test hash and then computes a test root node by applying a preset rule. The verifier checks that the signature is valid using a data whose authenticity is certified by the issuing authority.