Security News > 2023 > March > Experts Discover Flaw in U.S. Govt's Chosen Quantum-Resistant Encryption Algorithm

A group of researchers has revealed what it says is a vulnerability in a specific implementation of CRYSTALS-Kyber, one of the encryption algorithms chosen by the U.S. government as quantum-resistant last year.

The underlying idea is that the physical effects introduced as a result of a cryptographic implementation can be used to decode and deduce sensitive information, such as ciphertext and encryption keys.

One of the popular countermeasures to harden cryptographic implementations against physical attacks is masking, which randomizes the computation and detaches the side-channel information from the secret-dependent cryptographic variables.

"The basic principle of masking is to split each sensitive intermediate variable of the cryptographic algorithm into multiple shares using secret sharing, and to perform computations on these shares," another group of researchers explained in 2016.

"From the moment that the input is split until the shared output of the cryptographic algorithm is released, shares of the sensitive intermediate variables are never combined in a way that these variables are unmasked, i.e. the unshared sensitive variables are never revealed. Only after the calculation has finished, the shared output is reconstructed to disclose its unmasked value."

"There exist papers that attack pretty much every cryptographic algorithm using side-channels. Countermeasures are developed, and many of the attacks aren't realistic or practical in real-world scenarios."

News URL

https://thehackernews.com/2023/03/experts-discover-flaw-in-us-govts.html