Ring signature with divided private key

The ring signature is a group signature without a group manager, so that a signer realizes a signature in the name of the group. In some situations it is necessary for a message to be signed by more than one persons. The scheme of the ring signature with divided key is an algorithm which ensures realizing a key signature by a group of k entities from a group of n entities. Because of the way this scheme is elaborated, each signer has his own private key, which he uses in the signing phase. Checking the key is realized by using a single common public key. The signature scheme is based on the problem of the discrete logarithm. This cryptographic primitive ensures the anonymity of the signature, which is a ring signature.