1=pod 2 3=head1 NAME 4 5BN_security_bits - returns bits of security based on given numbers 6 7=head1 SYNOPSIS 8 9 #include <openssl/bn.h> 10 11 int BN_security_bits(int L, int N); 12 13=head1 DESCRIPTION 14 15BN_security_bits() returns the number of bits of security provided by a 16specific algorithm and a particular key size. The bits of security is 17defined in NIST SP800-57. Currently, BN_security_bits() support two types 18of asymmetric algorithms: the FFC (Finite Field Cryptography) and IFC 19(Integer Factorization Cryptography). For FFC, e.g., DSA and DH, both 20parameters B<L> and B<N> are used to decide the bits of security, where 21B<L> is the size of the public key and B<N> is the size of the private 22key. For IFC, e.g., RSA, only B<L> is used and it's commonly considered 23to be the key size (modulus). 24 25=head1 RETURN VALUES 26 27Number of security bits. 28 29=head1 NOTES 30 31ECC (Elliptic Curve Cryptography) is not covered by the BN_security_bits() 32function. The symmetric algorithms are not covered neither. 33 34=head1 SEE ALSO 35 36L<DH_security_bits(3)>, L<DSA_security_bits(3)>, L<RSA_security_bits(3)> 37 38=head1 HISTORY 39 40The BN_security_bits() function was added in OpenSSL 1.1.0. 41 42=head1 COPYRIGHT 43 44Copyright 2017-2019 The OpenSSL Project Authors. All Rights Reserved. 45 46Licensed under the Apache License 2.0 (the "License"). You may not use 47this file except in compliance with the License. You can obtain a copy 48in the file LICENSE in the source distribution or at 49L<https://www.openssl.org/source/license.html>. 50 51=cut 52