A method of securely processing a digital signal comprising: a) generating a public encryption key for use with a first logical circuit and a second logical circuit separate from said first logical circuit; b) accessing an encrypted signal at said first logical circuit; c) determining a first decryption key for said encrypted signal at said second logical circuit; d) encrypting said first decryption key at said second logical circuit using said public encryption key; e) transferring said encrypted first decryption key from said second logical circuit to said first logical circuit over a communication link; f) at said first logical circuit, decrypting said encrypted first decryption key using a secret key to determine said first decryption key; and g) at said first logical circuit, decrypting said encrypted signal using said first decryption key; wherein the method further comprises: monitoring the decrypted signal to detect a configuration message comprised within the decrypted signal, the configuration message comprising one of new encryption parameters used for the generation of the public encryption key and replacement program code for controlling the generation of keys and the encryption of keys; and if the configuration message is detected, storing the one of new encryption parameters and replacement program code comprised within the configuration message in a local memory of at least one of the first and second logical circuits. a) generating a public encryption key for use with a first logical circuit and a second logical circuit separate from said first logical circuit; b) accessing an encrypted signal at said first logical circuit; c) determining a first decryption key for said encrypted signal at said second logical circuit; d) encrypting said first decryption key at said second logical circuit using said public encryption key; e) transferring said encrypted first decryption key from said second logical circuit to said first logical circuit over a communication link; f) at said first logical circuit, decrypting said encrypted first decryption key using a secret key to determine said first decryption key; and g) at said first logical circuit, decrypting said encrypted signal using said first decryption key; wherein the method further comprises: monitoring the decrypted signal to detect a configuration message comprised within the decrypted signal, the configuration message comprising one of new encryption parameters used for the generation of the public encryption key and replacement program code for controlling the generation of keys and the encryption of keys; and if the configuration message is detected, storing the one of new encryption parameters and replacement program code comprised within the configuration message in a local memory of at least one of the first and second logical circuits. monitoring the decrypted signal to detect a configuration message comprised within the decrypted signal, the configuration message comprising one of new encryption parameters used for the generation of the public encryption key and replacement program code for controlling the generation of keys and the encryption of keys; and if the configuration message is detected, storing the one of new encryption parameters and replacement program code comprised within the configuration message in a local memory of at least one of the first and second logical circuits.