How to use a Hardware Security Module (HSM) Securely

The announcement yesterday of this talk about HSM hacking on the BlackHat 2019 program has caused a stir, and for good reason: the authors claim to have discovered remote unauthenticated attacks giving full control of an HSM and complete access to keys and secrets stored on it...

Google recently announced a project to produce tests for cryptographic libraries to detect common weaknesses. Piloted by star cryptographers Daniel Bleichenbacher and Thai Duong, this is an exciting development for us at Cryptosense, and not just because they cite our CRYPTO '12 paper in their RSA tests.

In 2014 I wrote a piece for this blog on RSA PKCS#1v1.5 encryption and why we need to get rid of it. At the time, the list of algorithms and padding modes to be included in the W3C WebCrypto API was under discussion, and I wanted to argue for the exclusion of this mode from the API. In the end it was indeed left out.

In the standard API for HSMs and other cryptographic hardware, PKCS#11, key-wrapping refers to the process of encrypting one key stored in hardware with another in order to send the first key somewhere else in a secure way. This operation has been the source of a whole series of security vulnerabilities, in particular because the encryption modes are often vulnerable to padding oracle attacks.