NAME

Crypt::Eksblowfish::Family - Eksblowfish cipher family

SYNOPSIS

use Crypt::Eksblowfish::Family;

$family = Crypt::Eksblowfish::Family->new_family(8, $salt);

$cost = $family->cost;
$salt = $family->salt;
$block_size = $family->blocksize;
$key_size = $family->keysize;
$cipher = $family->new($key);

DESCRIPTION

An object of this class represents an Eksblowfish cipher family. It contains the family parameters (cost and salt), and if combined with a key it yields an encryption function. See Crypt::Eksblowfish for discussion of the Eksblowfish algorithm.

It is intended that an object of this class can be used as the "-cipher" parameter to Crypt::CBC and similar systems. Normally that parameter is the name of a class, such as "Crypt::Blowfish", where the class implements a block cipher algorithm. The class provides a new constructor that accepts a key. In the case of Eksblowfish, the key alone is not sufficient. An Eksblowfish family fills the role of block cipher algorithm. Therefore a family object is used in place of a class name, and it is the family object the provides the new constructor.

CONSTRUCTOR

Crypt::Eksblowfish::Family->new_family(COST, SALT)

Creates and returns an object representing the Eksblowfish cipher family specified by the parameters. The SALT is a family key, and must be exactly 16 bytes. COST is an integer parameter controlling the expense of keying: the number of operations in key setup is proportional to 2^COST.

METHODS

$family->cost

Extracts and returns the cost parameter.

$family->salt

Extracts and returns the salt parameter.

$family->blocksize

Returns 8, indicating the Eksblowfish block size of 8 bytes.

$family->keysize

Returns 0, indicating that the key size is variable. This situation is handled specially by Crypt::CBC.

$family->new(KEY)

Performs key setup on a new instance of the Eksblowfish algorithm, returning the keyed state. The KEY may be any length from 1 byte to 72 bytes inclusive. The object returned is of class Crypt::Eksblowfish; see Crypt::Eksblowfish for the encryption and decryption methods.

Note that this method is called on a family object, not on the class Crypt::Eksblowfish::Family.

$family->encrypt

This method nominally exists, to satisfy Crypt::CBC. It can't really be used: it doesn't make any sense.

SEE ALSO

Crypt::CBC, Crypt::Eksblowfish

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

Copyright (C) 2006 Andrew Main (Zefram) <zefram@fysh.org>

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.