System for encrypted facsimile transmission

摘要

In facsimile transmission secured against unauthorised access, the required transmission-side encryption can be carried out at the digital level and the encrypted image signal can be transmitted in analog form following conversion to the analog level. So that the analog signal encrypted here does not need to be limited for the transmission on the transmission side in terms of bandwidth, i.e. a loss of information in the image signal reconstructed on the reception side having to be accepted, it is proposed that the transmission-side encryption and the reception-side decryption of the code words comprising n bits and representing the scanning values at the digital level be carried out with the modulo 2<n> code pulse string generated by a quasi-random generator. <IMAGE>