Résumé: Certain weaknesses in the algebraic structure of recently proposed fast encryption algorithm for multimedia FEA-M are pointed out. It is shown that, when the secret key consists of k bits, under realistic chosen and known plaintext attacks, the secret key recovery has complexity proportional to 2k<superscript>2 and k<superscript>4, respectively, implying that FEA-M is an insecure algorithm even if the secret keys of 4096 bits are employed.

Langue: Anglais