Decrypting a Base 64 Encoded File

I don't believe there is a Forum dedicated to Cryptography so I will post in the C forum since the program I've used to decode a base 64 encoded file was written in C. I have been given a base64 encoded file and I have managed to remove the base64 encoding which was easy enough. The second phase is to remove the encryption so I can view the original plain text. I believe one way to do this is to just try all the keys from 0-255 which would take ages. Are there other ways to remove the decryption? Are there any resources that you guys know of that would better my understanding of how to decrypt a file. I have attached the program that I used to remove the base64 (b64.c) encoding as well as that .dat (encoded) file and .bin (decoded) file. Thanks

[Salem]

http://en.wikipedia.org/wiki/Frequency_analysis

Ive looked into this problem more and it appears that the plaintext message has been enciphered using the latin square or rail fence cipher which are both permutation or transposition ciphers. I'm tempted to do just a brute force attack to find the key and recover the plain text because they key is just 8 bits long lol. With my quad core machine I can do that in the blink of an eye. Its much easier than doing a frequency analysis since I don't have to go through the lengthy process of trial and error. The best way to do this is to write a program is C or Java that will try all the keys. Does anyone know how I would do this?