Extractors against Side-Channel Attacks: Weak or Strong?

Randomness extractors are important tools in cryptography. Their goal is to compress a high-entropy source into a more uniform output. Beyond their theoretical interest, they have recently gained attention because of their use in the design and proof of leakage-resilient primitives, such as stream ciphers and pseudorandom functions. However, for these proofs of leakage resilience to be meaningful in practice, it is important to instantiate and implement the components they are based on. In this context, while numerous works have investigated the implementation properties of block ciphers such as the AES Rijndael, very little is known about the application of side-channel attacks against extractor implementations. In order to close this gap, this paper instantiates a low-cost hardware extractor and analyzes it both from a performance and from a side-channel security point of view. Our investigations lead to contrasted conclusions. On the one hand, extractors can be efficiently implement...

• Type: Journal
• Year: 2011
• Where: CHES
• Authors: Marcel Medwed, François-Xavier Standaert
• Keywords: Block Ciphers, CHES 2011, Cryptology, Implementation Properties, Stream Ciphers