A control entity communicates with an entity to be controlled so as to effect a control, a secret key being associated with the control entity. These entities share public parameters, a second public parameter being a combination of a first public parameter of the said plurality with the secret key. At the level of the entity to be controlled, a random value is generated, a first message is transmitted to the control entity, this first message comprising at least one value obtained by combining the first public parameter with the random value; and a second message is transmitted to the control entity, this second message comprising at least one value obtained by combining the first random value, a secret key of the entity to be controlled and a value received from the control entity. One of the values included in the first or the second message is based on the second public parameter.