-----BEGIN PGP SIGNED MESSAGE----- Another possible problem with the technique is that the multiple solutions are all valid. For example, with two nestings and a = 11/2, b = 8, c = 25/2, d = 3, P = 16 I obtain g = 903 + 4675/4 x + 3025/8 x^2 mod 16 g' = 7 + 3/4 x + 81/8 x^2 mod 16 where the g' is obtained from g by reducing the coefficients mod 16. Solving the resulting equations yields two solutions: a = 11/2, b = 8, c = 25/2, d = 3 (what I chose) a = 31/2, b = 6, c = 17/2, d = 2 Plugging in the second solution: h = 359 + 6851/4 x + 16337/8 x^2 mod 16 h' = 7 + 3/4 x + 81/8 x^2 mod 16 Notice that h' equals g'! So the other solution can be used to form the same polynomial (which we already saw doesn't encrypt uniquely). Can this other solution be used for decryption as well? I'd check but I've REALLY got to go study now :-) -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLMXZsYOA7OpLWtYzAQFjMAP/Si1RuZjfnBNjLauB20rXaUXQMQqyiWBU n/ur7ckXSEmWnADYQqZqCy1tb/+vf5zThQD2IpbF5IH8roxYG99nZQBvvtZAQfEO 3EdbM1esMTS/I0DwcLqkuG26GNNWYGZWi8MQ/0+eXfMa9BXZvkDTuuVBzzHBSXxW 84CVKvitZ68= =FeJW -----END PGP SIGNATURE-----