tfcrypt: fix "-M mac -u" failing to decrypt data due to missing ctr.

[tfcrypt.git] / README

diff --git a/README b/README
index f26c3461c4d2fb4cd106c0181519bd8f910f7dd1..a5473cb463fa21e902bbd789bc24cebdb825f072 100644 (file)
--- a/README
+++ b/README
@@ -10,18 +10,16 @@ Blowfish and Twofish ciphers, which are in use still up to today.
 
 tfcrypt is actually a frontend for Threefish with (by default) XTS mode of operation.
 As a key it uses either password or keyfile, which is then hashed many times
-with Skein hash function. Default key length is 1280 bits (160 bytes).
+with Skein hash function.
 
 This program is incompatible with older, "tf1024" tfcrypt version. This version aims to
 provide a portable encryption tool to encrypt fixed media such as disks and archive files,
-as well as to provide decades long privacy for encrypted data. That's why it uses 1024 bit
-encryption and, unlike older version, extends key size to 1280 bits, eliminates tweak feature
-from Threefish and uses either XTS (by default) or OCB modes of operation instead,
-to encrypt fixed media in a secure undetectable way.
+as well as to provide decades long privacy for encrypted data.
+Supported modes of operation: CTR, ECB, CBC, XTS and arbitrary long keystream.
 
-Supported modes of operation: CTR, ECB, CBC, XTS, OCB and arbitrary long keystream.
-OCB mode does not use Skein hash function to hash and verify message, instead, it does
-a single pass crypt and verify, thus, it is faster than other modes when both crypt and verify.
+Additionally, this version provides a way to virtually "extend" key size to 1280 bits,
+by enabling "fullkey" option or changing "do_full_key" default setting in tfcrypt_defs.h.
+In this mode, tweak is ignored, and filled with extended key material.
 
 THREEFISH NOTES
 
@@ -29,12 +27,8 @@ Please note that this encryption software includes Threefish cipher, which is te
 slow on 32 bit systems. This way, it cannot be efficiently used on pure 32 bit machines.
 
 Threefish contained here is stripped off of it's tweak property, thus, it is turned into a
-regular block cipher. To add tweakability, either XTS or OCB modes of operation are used.
-Default wide block size is 4096 bytes. Author strongly believes that Threefish _may_ be subject
-to related key attacks when used in a tweaked mode, so this property is easy to remove.
-Because tweak occupied another 192 bits of key material, these 192 bits are added to effective
-key length. Another key word is extracted from the sum of all the user key words, thus,
-another 64 bits. Total +256 additional bits of key = 1280 key bits.
+regular block cipher. To add tweakability, XTS modes of operation is used.
+Default wide block size is 4096 bytes.
 
 SKEIN NOTES
 
@@ -58,7 +52,7 @@ LICENSE
 
 This tfcrypt, unlike it's previous version, is copyrighted:
 
-       Copyright (C) Andrey Rys <rys@lynxlynx.ru>, 2012-2018.
+       Copyright (C) Andrey Rys <rys@lynxlynx.ru>, 2012-2019.
 
 It maybe freely used by anyone who agrees to the terms and conditions of the MIT license.