Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm and the window size is not chosen appropriately. This for example affects use of ElGamal in OpenPGP.

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ROHNP: Key Extraction Side Channel in Multiple Crypto Libraries

Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the gcryeccecdsasign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. T...