                S K S  -  P O C K E T   C R Y P T O G R A F Y 
				
Web page: http://sks.merseine.nu

Introduction
============

SKS is a public-key, command-line application for encryption/authentication,
based on Elliptic Curve Cryptografy (ECC). Its minimalist design points to
simple, light, fast, easy-to-use and multiplatform product, unencumbered by 
patents that is indeed distributed under GPL. All these features are given 
along with high quality cryptografy.

Its cryptografic elements are:

    * Public-key module: elliptic curve over GF (2^191)
    * Simmetric-key module: AES 192-bits key, with CTR mode
    * Hash (for signatures, HMAC and passwords): TIGER (192 bits)
    * PRNG module: /dev/urandom in Linux-Unix and CryptGenRandom in
      Windows

SKS can be ported/played on a diskette, doesn't need previous instalation and
can be used inmediatly.

Instalation
===========

SKS is a command-line application without complex instalation. The following
instructions are valid for x86-family CPU-based computers within *NIX or Windows
(2000, XP, NT) operating systems. It is valid also in older Windows 98/ME/95 but
some previous work must be done.

Unzip the '.zip' or '.bz2' file in any temporal folder; copy executable on any
folder pointed by 'PATH' enviroment variable. Go to temporal folder and do:

    sks -ki skspkr

This will load the public keys contained on given file 'skspkr'. One of the keys
is my personal key [00e14ca8]. Now you can test if binary comes from me:

    sks -v sks sks.sig     *** Linux-Unix ***
    sks -v sks.exe sks.sig *** Windows ***

which should say:

 [00e14ca8]: Manuel Pancorbo Castro <mpancorbo # wanadoo.es>
SKS OK. signature made at: 2004-05-10, 13:34

(the date may change). Now you can create your own public key:

    sks -kg > mykey

where 'mykey' is your public-key file, that can be distributed. The program asks
for textual brief description of the key and then asks for your password. Public
key is stored onto your keyring.

For Windows 98/ME/95/3.1 and DOS users
--------------------------------------

Before launching the program you *must* define the enviroment variable APPDATA:

    set APPDATA=<directory>

where <directory> is any existing folder on the disk with write access for you.
Do not put ending backslash [ \ ]; for example:

    set APPDATA=C:\Crypto
    set APPDATA="C:\My Documents"

It is highly recommended to put this definition in AUTOEXEC.BAT file.

Compilation
===========

Source code has been compiled without problems with 'gcc' and 'gcc-mingw' under
Windows. Other compilers may requiere 'makefile' revision. Simply do:

    make                    *** Linux-Unix ***
    make -f Makefile.w32    *** Windows ***

If you want to install (first get superuser privileges):

    make install                   *** Linux-Unix ***
    make -f Makefile.w32 install   *** Windows ***

I recommend to edit the 'Makefile' (or Makefile.w32) in order to customize the
compilation to your needs. All custom variables are at the beginning of the
file.

License
=======

SKS is distributed under GPL. Please read 'gpl.txt' in 'doc' folder. Anyway, the
author warns that unwise manipulation of code may yield a program which
resulting ciphertexts and signatures will not be recognized by ortodox
buildings.

Manual
======

The full manual is given under 'doc'-folder in html files, but only in Spanish
language. I apologize. A brief manual is obtained by typing 'sks' without
parameters (or 'sks -k' or 'sks -f'). Moreover, the source code and makefiles
are commented in English.

---------------------------------------------------------------------
Copyright (C) 2004-2006  Manuel Pancorbo Castro <mpancorbo@gmail.com>