  As a special type of factorization of finite groups, logarithmic signature
(LS) is used as the main component of cryptographic keys for secret key
cryptosystems such as PGM and public key cryptosystems like MST1, MST2 and
MST3. An LS with the shortest length is called a minimal logarithmic signature
(MLS) and is even desirable for cryptographic constructions. The MLS conjecture
states that every finite simple group has an MLS. Until now, the MLS conjecture
has been proved true for some families of simple groups. In this paper, we will
prove the existence of minimal logarithmic signatures for some sporadic groups.
