What is the best way to encrypt a file for sending it to another person? Lets say I want to encrypt a Word file, email it to someone, and they can open it using a password that we've agreed upon in advance, either over the phone or in person. What would I use? I assume I wouldn't use Truecrypt anymore.

Wow - hadn't heard of the TrueCrypt problem. My old multinational conglomerate employer relied on it (albeit a significantly older than released version).

Surely for a one off transfer it would be enough? Who are you worrying about getting this file?

Otherwise 7-Zip supports AES-256 which should be enough for today's climate. How do you know it doesn't have similar holes though?

Simply because the original developers stopped making new releases is no reason to mistrust or stop using it.

The encryption algorithms don't change from one release to another, other than some potential improvements in strengths of new keys generated.

Interesting. I hadn't seen the update that there might not be a problem with it. Still, it's a strange thing for the developers to do...

I already had 7-Zip installed but I didn't know it could do file encryption! AES-256 is good enough for me. Thanks for the suggestion!

*edit*
Any reason not to trust that? I'd imagine that more eyes are on TrueCrypt, so perhaps that would be safer...?

Any reason not to use gpg?

Just that I've never heard of it

*edit*
Ah, a little research explains to me that it's an implementation of PGP. Neat.

For my purposes, though, I think 7-Zip is the kind of lightweight and easy to use tool that I'm going to need. I'll be offering this as a suggestion to a couple people sending files back and forth, and I think the simplest solution is best (even though that phrase is never actually true in security ).

I'll try all of these solutions and see which ones I can best explain to non-technical people. Thanks!