22.9 Timing attacks
In the previous two chapters, we learned about attacks on the TLS Handshake and the TLS Record protocols, which use a padding oracle to compromise TLS security guarantees. In most cases, the padding oracle is a by-product of data-dependent timing differences that occur when a TLS implementation processes the received TLS messages.
While these attacks target the TLS Handshake or TLS Record protocol, the underlying reason – namely, the leakage of information about internally processed data – is an implementation issue. In cryptography, attacks that exploit such information are called side channel attacks.
More precisely, side channel attacks exploit unintended information leakage caused by the physical properties of the implementation of a cryptographic algorithm. Using the leaked information, Eve can infer intermediate values processed by the cryptographic algorithm and, based on these values, extract the secret values.
22.9.1 Side channel attacks
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