Decrypting Unix file

Accidentally, I encrypted a file while saving it in vi editor.
While saving I used :X and when asked for encryption key, I simply pressed ENTER key without any input.

Now, I want to decrypt the file.

I searched the forum, but unfortunately didn't get the proper solution. In one of the threads it asked to visit a particular link which I couldn't access.

Can anybody please help me .

Regards,
Ravi.

Please don't post twice - see your other thread