We appologize for making the following mistakes. - page 317, in the fifth line of the second paragraph, "E. Biham presented a known-plaintext attack and a chosen-plaintext attack ..." should read "E. Biham presented a known-plaintext attack and a chosen-ciphertext attack ..."; - page 320, in Eq. (1), "no outut" should read "no output"; -- Page 328, Reference 3 should read "R. Forr\'{e}. The H\'{e}non attractor as a keystream generator. In Abstracts of EuroCrypt'91, pages 76-81, 1991." - page 329, the publication year of Reference 23 should read "1999".