I don't know what Blowfish is, and you shouldn't assume that anyone else here will either. Since you downloaded blowfish, your best bet for advice on it, is to contact the person that wrote it. Also, I noted that you mentioned an encryption. The only way for encrypted material can be recognized is if it is decrypted first, which is an excellent way of having things go really wrong with your computer.
Unless you know what Blowfish does, and you're willing to chance that it's not going to do anything else, I'd recommend getting rid of it, then checking your system thoroughly for viruses, trojans, malware. adware, spyware, and almost any other kind of *ware that can be thought of.