Trailrunner7 quotes a report from On the Wire: Google has released a new set of tests it uses to probe cryptographic libraries for vulnerabilities to known attacks. The tests can be used against most kinds of crypto algorithms and the company already has found 40 new weaknesses in existing algorithms. The tests are called Project Wycheproof, and Google's engineers designed them to help developers implement crypto libraries without having to become experts. Cryptographic libraries can be quite difficult to implement and making errors can lead to serious security problems. Attackers often will look for weak crypto implementations as a means of circumventing strong encryption in a target app. Among the issues that Google's engineers found with the Project Wycheproof tests is one in ECDH that allows an attacker to recover the private key in some circumstances. The bug is the result of some libraries not checking the elliptic curve points that they get from outside sources. "In cryptography, subtle mistakes can have catastrophic consequences, and mistakes in open source cryptographic software libraries repeat too often and remain undiscovered for too long. Good implementation guidelines, however, are hard to come by: understanding how to implement cryptography securely requires digesting decades' worth of academic literature. We recognize that software engineers fix and prevent bugs with unit testing, and we found that many cryptographic issues can be resolved by the same means," Daniel Bleichenbacher and Thai Duong, security engineers at Google, said in a post announcing the tool release. "Encodings of public keys typically contain the curve for the public key point. If such an encoding is used in the key exchange then it is important to check that the public and secret key used to compute the shared ECDH secret are using the same curve. Some libraries fail to do this check," Google's documentation says.