Hi Herbert, Is the following code in crypto_alloc_sync_skcipher() wrong: /* Only sync algorithms allowed. */ mask |= CRYPTO_ALG_ASYNC | CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE; in its specification of CRYPTO_ALG_ASYNC? Given what the docs say: The mask flag restricts the type of cipher. The only allowed flag is CRYPTO_ALG_ASYNC to restrict the cipher lookup function to asynchronous ciphers. Usually, a caller provides a 0 for the mask flag. ^^^^^^^^^^^^ or are the docs wrong? David