In a method for searching for an entity belonging to a set of entities, a verifier device and the entities are arranged so as to exchange information via at least one communication channel. Each entity has a first respective identifier from which a plurality of representatives can be obtained. According to the method, a first identification word (mi; p(Xi)), which is related to an entity for which a search is carried out, is obtained in the verifier device. The first identification word is formed by applying a first encoding function to the first identifier of the entity for which the search is being carried out so as to depend on a sub-portion of the plurality of representatives that can be obtained from said first identifier. The sub-portion is predetermined by at least one variable parameter. The first identification word, obtained on the communication channel, is transmitted from the verifier device.