Encrypting Data

I am looking at methods for encrypting and decrypting data stored in the database (actually storing the encrypted strings).  However, I really like the Symetric Encrypting Method that uses a key file except for the fact that the key needs to be generated on their machine.  Is there a way I can use a key file/hash that I can generate on my machine and deploy it with the program to my users?

Thanks,
Greg