We introduce a natural generalization of the golden cryptography, which uses
general unimodular matrices in place of the traditional Q-matrices, and prove
that it preserves the original error correction properties of the encryption.
Moreover, the additional parameters involved in generating the coding matrices
make this unimodular cryptography resilient to the chosen plaintext attacks
that worked against the golden cryptography. Finally, we show that even the
golden cryptography is generally unable to correct double errors in the same
row of the ciphertext matrix, and offer an additional check number which, if
transmitted, allows for the correction.Comment: 20 pages, no figure