OtpOpen Files

INSTALLATION
============

WINDOWS
*******
As Administrator:
otp-1.0.2-win-3js.exe

LINUX
*****
As Root:
chmod u+x otp-1.0.2-i686-3js.run
otp-1.0.2-i686-3js.run

ALL OTHERS
**********
As root:
1. Unpack otp-1.0.2-src-3js.zip, e. g. in /usr/local/src
2. "cd" to the "otp-1.0.2" directory
3. qmake otp.pro
4. make
5. make install
6. make clean
7. To uninstall: make uninstall


What is OTP?
============

OTP stands for one-time pad and is a symmetric encryption method using a
random key. The key length must be the same length as the message to be
encrypted. Moreover, the random key must only be used once. Overall, four
conditions must be met before the OTP encryption can not be broken! The key

1) must be as long as the message.
2) must be random and distributed equally.
3) must be kept secret.
4) should not be used again, not even partially.

For more information about one-time pad encryption you can read
http://en.wikipedia.org/wiki/One-time_pad


How to Use OTP?
===============

First you have to create a large key file (several MB or GB) with random
data. That's not so easy, because of that OTP can't do it for you for
security reasons. An ordinary computer is not able to generate such a large
random file in good quality. Moreover the pseudo-random numbers, which may
produce a computer are not random enough, and would be a security risk.

With OTP you can encrypt/decrypt normal text within the OTP editor or any
files. After encrypting normal text you can copy and paste it into your
email program or elsewhere to send it to your communication partner.


Some Notes on Using OTP
=======================

- IF POSSIBLE USE OTP ONLY ON A SECOND STANDALONE AND INTERNET-FREE
  COMPUTER.

- THE DECRYPTED DATA MUST REMAIN ON THAT INTERNET-FREE COMPUTER.

- THE ENCRYPTED DATA MUST BE TRANSFERRED TO THE INTERNET COMPUTER
  TO SEND THEM.

- IF THE ENCRYPTED DATA IS TOO BIG FOR SENDING IT VIA EMAIL JUST SEND
  IT BY SNAIL MAIL.

* It would be a good idea to create a random key file by yourself, for
  example by recording a video file with road traffic or a sound file
  with street noise or the noise of a waterfall (if you have one nearby)
  etc.

* Save your key file only on a writable and removable storage medium!

* Make sure that you are not connected to the internet while your key file
  is accessable!

* Remove the storage medium from your computer after using the key file!

* Give a copy of the key file to your communication partner. Don't use
  the internet for that! Give him the file personally. For each
  communication partner you need a different key file! In order to keep
  track of the key files you should use meaningful file names, for example
  Myname-Yourname.key

* If you want to encrypt several files at onceyou should number them, for
  example Yourname-SecretStuff_1.txt etc. This makes it possible for
  your communication partner to decrypt the files in the right order.
  Otherwise a wrong decrypting order would damage your and partner's key
  file, and you and your partner would have to exchange new key files.

* You can use OTP only to encrypt text and files that are intended for
  another person, which has the same key file as you. This means that you
  can't use OTP to encrypt text and files for personal use because you
  can't decrypt them anymore. The reason is that the key needed for this
  does not exist anymore. The key was deleted right after encryption. Only
  your communication partner can decrypt it!

* As you can see, OTP is not as easy to use as GnuPG or similar programs,
  but it is not breakable when the above four conditions are satisfied and
  you have no malware (keylogger or similar stuff) on your computer.