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BN_security_bits(3)                 OpenSSL                BN_security_bits(3)



NAME
       BN_security_bits - returns bits of security based on given numbers

LIBRARY
       libcrypto, -lcrypto

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.

HISTORY
       BN_security_bits() was added in OpenSSL 1.1.0.

SEE ALSO
       DH_security_bits(3), DSA_security_bits(3), RSA_security_bits(3)

COPYRIGHT
       Copyright 2017 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>.



1.1.1                             2018-09-17               BN_security_bits(3)