future proof file encryption

[Robert J. Hansen]

peter wrote:
> Is it true to say then, that if you wanted someone to be able to
> decrypt a (symmetrically encrypted) file, they'd need to know the
> algorithm used, the key and they'd also have to use the same program
> to decrypt as used to encrypt the file?

Let's not use words like "algorithm" and "program", since they have
fairly precise technical meanings and I don't think you want to get
bogged down in jargon.

You need to know the key, and you need a decrypter that's compatible
with whatever you used to encrypt.

GnuPG conforms to the OpenPGP standard for cryptography.  That means
there are ... what ... 14 or so compatible implementations.  You don't
have to rely on GnuPG; there are a lot of other options out there.  This
is very good for purposes of long-term storage.