BN_security_bits - returns bits of security based on given numbers
 #include <openssl/bn.h>
 int BN_security_bits(int L, int N);
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).
ECC (Elliptic Curve Cryptography) is not covered by the
  BN_security_bits() function. The symmetric algorithms are not covered
  neither.
DH_security_bits(3), DSA_security_bits(3),
  RSA_security_bits(3)
The BN_security_bits() function was added in OpenSSL 1.1.0.
Copyright 2017-2019 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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>.