GnuPG decryption problem

[David Smith]

m.aflakparast at ut.ac.ir wrote:
> I need to decrypt .gz.gpg files (e.g. 70195_C1_WTCCCT442627.CEL.gz.gpg).
> I have the encryption key(passphrase).

Remember that the passphrase is not the key.  The key is stored in a
file, and that file is protected by the passphrase so that only people
who know the passphrase can use it.

> I used Gnp4win and ran into this error:
>      "bad session key"
> Then I downloaded gnupg-1.4.9 for windows from the following link:
> 
> http://techgenie.com/latest/how-to-install-gnupg-1-4-9-on-windows-xp-vista-and-7/
> 
> I followed the instructions and installed.
> Now, when I use the full path to the gpg program (gpg.exe)
> in the command line, and enter the following command:
> 
> gpg --decrypt "myfile.gpg"
> 
> I am asked a passphrase, but the problem is that it is not possible to
> write any thing in fron of the statement" Enter Passphrase:", e.i.
> whatever you type, nothing appears on the screen!

That is probably intentional, to stop someone seeing your passphrase by
looking over your shoulder.

Personally, rather than using --decrypt, I'd use --decrypt-file.  That
might help.