BN_SECURITY_BITS
Section: OpenSSL (3)
Updated: 2020-07-28
Page Index
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>.