Formal Methods and the KRACK Vulnerability

On Monday, the KRACK vulnerability to WPA2 was revealed in a paper by Mathy Vanhoef and Frank Piessens. KRACK enables a range of attacks against the protocol, resulting in a total loss of the privacy that the protocol attempts to guarantee. For more technical details on the attack, the website and the Key Reinstallation Attacks […]

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Part two: Specifying HMAC in Cryptol

This is the second in a series of three blog posts detailing the use of SAW and Cryptol to prove the correctness of the HMAC implementation in Amazon’s s2n TLS library. Part one: Verifying s2n HMAC with SAW. Part three: Proving Program Equivalence with SAW. In the first post, we described how we proved equivalence between a mathematical description […]

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Part one: Verifying s2n HMAC with SAW

In June 2015, Amazon introduced its s2n library, an open-source TLS library that prioritizes simplicity. A stated benefit of this simplicity is ease of auditing and testing. Galois recently collaborated with Amazon to show that this benefit extends to verifiability by proving the correctness of s2n’s implementation of the keyed-Hash Message Authentication Code (HMAC) algorithm. To construct this […]

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