This program can decript under 3 seconds an exor encrypted text (up to 8 MB) with a key of size 8.
Use one of the demo files or create one of your own
$ javac Encrypter.java
$ java Encrypter 12345678 <in >out
Compile the decrypter (you need a NVidia GPU with CUDA architecture >= 2.1)
$ nvcc exor.cu -o exor -arch=sm_21
Then run it
$ ./exor <secret1 >out