NAME

       BN_security_bits - returns bits of security based on given numbers

SYNOPSIS

        #include <openssl/bn.h>

        int BN_security_bits(int L, int N);

DESCRIPTION

       BN_security_bits() returns the number of bits of security provided by a specific algorithm
       and a particular key size. The bits of security is defined in NIST SP800-57. Currently,
       BN_security_bits() support two types of asymmetric algorithms: the FFC (Finite Field
       Cryptography) and IFC (Integer Factorization Cryptography). For FFC, e.g., DSA and DH,
       both parameters L and N are used to decide the bits of security, where L is the size of
       the public key and N is the size of the private key. For IFC, e.g., RSA, only L is used
       and it's commonly considered to be the key size (modulus).

RETURN VALUES

       Number of security bits.

NOTES

       ECC (Elliptic Curve Cryptography) is not covered by the BN_security_bits() function. The
       symmetric algorithms are not covered neither.

SEE ALSO

       DH_security_bits(3), DSA_security_bits(3), RSA_security_bits(3)

HISTORY

       The BN_security_bits() function was added in OpenSSL 1.1.0.

COPYRIGHT

       Copyright 2017-2019 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use this file except in
       compliance with the License.  You can obtain a copy in the file LICENSE in the source
       distribution or at <https://www.openssl.org/source/license.html>.