of access control protocol between a key and an electronic lock

The invention concerns an access control protocol between an electronic key and lock. When the key (EKkj) and the lock (Bi) are present, the following steps are carried out: transmitting (aij) from the lock (Bi) to the key (EKkj) a random variable message inciting authentication; computing then transmitting from the key (EKkj) and from the lock (Bi) the random variable and authentication data (DAj); verification by the lock (Bi) of the authenticity of the signature value on the basis of the data (DAj). Allowing or prohibiting access upon positive or negative reply concerning verification. The invention is applicable to management of trustee securities by officials.