Patent ID: 6219791
Filing Date: 2001-04-17
Classification: H04L

Abstract:
An apparatus for generating and verifying encrypted text, said apparatus comprising:an input and an output;a data formatter coupled to said input for creating data packets, said data formatter formatting data into blocks and applying error detection codes;a data encryptor having a plain text input for receiving said data packets which include embedded error detection codes, said plain text input being coupled to said data formatter, and having an encrypted text output, said data encryptor further comprising a first key generator and means for creating encrypted data packets by encrypting said data packets using a key from said first key generator;a delay circuit having an encrypted text input coupled to the encrypted text output of the data encryptor, and having a delayed encrypted text output, said delay circuit compensating for delays in said apparatus;a data decryptor having an encrypted text input coupled to the encrypted text output of the data encryptor, and having a decrypted text output, said data decryptor further comprising a second key generator and means for creating decrypted data packets by decrypting the encrypted data packets using a key from said second key generator, said key from said second key generator being substantially equal to said key from said first key generator;an error detector having an input coupled to the decrypted text output of the data decryptor, and having an error output, wherein the error detector is configured to examine the embedded error detection codes in the decrypted data packets to determine if errors exist;a latch having an input coupled to said error detector, having a reset input, and an output, said latch latching when an error signal is received from said error detector; anda switch coupled between the delayed encrypted text output of the delay circuit and the output of the apparatus, and coupled to the output of the latch such that when the latch latches due to an error, the switch opens, preventing encrypted text from leaving the apparatus.