CryptoXor

CryptoXor encrypts a file with a key you provided using a XOR operation

Current Version: 1.0
Download : cryptoxor.tar.gz

Usage: ./cryptoxor <source_file> <key_file> <destination_file>

Example: ./cryptoxor Secret_Project.txt.gz secret.key Secret_Project.txt.gz.xored

Note for maximum security:
- Don't use keys smaller than the file to crypt/3
ex: if your file is 3MB big don't use a key smaller than 1MB. The shorter the key is, the simpler it's to decrypt, if you use a 1byte key it's very easy to find it out...
The Best is to use a key as long (or long) than file to crypt

- If you intend to crypt a text file, gzip it before (specially if you use a short key) because in a text file you have lots of time dot-enter (.\n), this can help to decrypt it (if you use a key that have the same length as you text file, you haven't this probleme)

- Don't use a text file to crypt (or gzip it before), for the same reason than above.
To create key you can use /dev/urandom or /dev/random, this make good keys, you can also take an image file (ex: cryptoxor.jpg) but without to many NULL character (see bellow). (A noisy image is ok)

- A XOR is done bit by bit, and a NULL character is 00000000, if you do a XOR with 00000000 (ex: 00000000 XOR 01101001) your result is 01101001 (see bellow)

- XOR is a eXclusif OR, the result is true (1) only if their is only one "1" in the to args, ex: 0 XOR 0 -> 0, 0 XOR 1 -> 1, 1 XOR 0 -> 1, 1 XOR 1 -> 0.

- To tranmit the key to another people, don't use mail... (or crypted one), the best is to give the key physicaly to others people.



Jeb@jeb.com.fr