Combined Conditional Access Development & Support, LLC (ccad)

General Instrument Corporation

Combined Conditional Access Development and Support, LLC

An Tonthat

Lawrence W Tang

Eric J Sprunk

Michael W Johnson

Patrick Charles Murray

John Edward Rudy

Madhusudhan R Penugonda

An apparatus, method, system and computer-readable medium are provided for preserving an encryption of data when confronted by an attack, such as a side channel analysis (SCA) attack based on a statistical analysis. In some embodiments, hardware, software, and/or firmware associated with an encryption calculation may be exercised or accessed during a background operation when an actual or real operation is not taking place. During the background operation, dummy values for data and one or more keys may be input to the hardware. A switching between the real operation and the background operation may take place seamlessly such that measurement of a physical characteristic associated with the hardware is indistinguishable in terms of when the real and background operations are active. In this manner, the secrecy of a key used in connection with the real operation may be preserved.

Preservation of encryption

Aspects of the disclosure relate to a protocol for communication of information. The protocol can be a non-standard universal serial bus (USB) protocol and can guarantee bandwidth and latency for information communication between a USB host and a single USB device. In one aspect, the non-standard USB protocol can employ a repeating message sequence that is fixed, or static, and preconfigured, the sequence comprising alternating transmission of messages between a first device (e.g., a host device) and a second device (e.g., a peripheral device).

Protocol for communication

Encryption operation with real data rounds, dummy data rounds, and delay periods

According to the invention, a circuit that is capable of automated scan testing is disclosed. Included in the circuit are a cryptographic engine, a digital circuit, an input pin, and an output pin. The cryptographic engine capable of performing at least one of encryption and decryption of one or more digital signals. The digital circuit includes combinatorial logic and a number of memory cells. The memory cells have scan inputs connected serially in a scan chain. The input pin and output pin are coupled to the scan chain. At least one of the input pin and the output pin carries at least some cipher text data of the scan chain.

Secure scan

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San Diego, CA, United States of America

An Tonthat