=pod
+=for comment openssl_manual_section:7
+
=head1 NAME
-Modes of DES - the variants of DES and other crypto algorithms of OpenSSL
+des_modes - the variants of DES and other crypto algorithms of OpenSSL
=head1 DESCRIPTION
-Several crypto algorithms fo OpenSSL can be used in a number of modes. Those
+Several crypto algorithms for OpenSSL can be used in a number of modes. Those
are used for using block ciphers in a way similar to stream ciphers, among
other things.
=item *
-OFB mode is not self-synchronising. If the two operation of
+OFB mode is not self-synchronizing. If the two operation of
encipherment and decipherment get out of synchronism, the system needs
-to be re-initialised.
+to be re-initialized.
=item *
-Each re-initialisation should use a value of the start variable
+Each re-initialization should use a value of the start variable
different from the start variable values used before with the same
key. The reason for this is that an identical bit stream would be
produced each time from the same parameters. This would be
=item *
If the first and last key are the same, the key length is 112 bits.
-There are attacks that could reduce the key space to 55 bit's but it
-requires 2^56 blocks of memory.
+There are attacks that could reduce the effective key strength
+to only slightly more than 56 bits, but these require a lot of memory.
=item *
L<blowfish(3)|blowfish(3)>, L<des(3)|des(3)>, L<idea(3)|idea(3)>,
L<rc2(3)|rc2(3)>
+
+=cut
+