UNIX for Dummies Questions & Answers

First I will admit that I am completely new to UNIX. That being said, I accidentally encrypted a file in the VI editor. I realize that there are similar posts to this one, but the thing is I know the encryption key I used. I would like to unencrypt the file. I want it to stop prompting me for the key each time I open it. Is there any way to do this? Thanks in advance

crypt < encrypted.file > unencrypted.file

crypt will prompt you for your key.