Abstract: According to an embodiment, a method of preventing the alteration of a stored data value is disclosed. The method comprises coupling a first electronic fuse to an output control circuit; coupling a second electronic fuse to the output control circuit; decoding the states of the first electronic fuse and the second electronic fuse after a first processing step to generate a first decoded state; and decoding the states of the first electronic fuse and the second electronic fuse after a second processing step to generate a second decoded state different from the first decoded state; wherein the output control circuit maintains the second decoded state after an attempt to alter a state of an electronic fuse of the first electronic fuse and the second electronic fuse. A circuit for preventing the alteration of a stored data value is also described.

Abstract: In one embodiment, a cryptographic device is provided. The cryptographic device includes a persistent memory and a decryption control circuit coupled to the persistent memory. The decryption control circuit is configured to receive an encrypted data stream and decrypt a first portion of the encrypted data stream using a first cryptographic key stored in the persistent memory, the first portion including a second cryptographic key. The decryption circuit is configured to decrypt a second portion of the encrypted data stream using the second cryptographic key, the second portion of the encrypted data stream including payload data.

Abstract: The present invention provides redundant, inverse multiplexing over ATM (R-IMA). An ATM control system may include line interface circuitry, transmission convergence logic, IMA logic, and a cross-connect coupling the IMA logic of the redundant ATM control systems to control activity. The line interface circuitry terminates n DSx lines and is adapted to receive n incoming ATM over DSx traffic streams and transmit n outgoing ATM over DSx traffic streams corresponding to the n DSx lines. The transmission convergence logic is adapted to recover incoming ATM cell streams from the incoming ATM over DSx streams and generate the outgoing ATM over DSx traffic streams to form n outgoing ATM cell streams. The IMA logic is adapted to combine the incoming n ATM cell streams to form an incoming combined ATM cell stream, and distribute ATM cells from an outgoing combined ATM cell stream to create the n outgoing ATM cell streams.