Incidentally I also use Decoy as one method of PGP public key verification. The "decoy" picture is a screenshot of my public key. The photo hidden behind the decoy is a picture of me, holding up my drivers license and an index card with my username. The picture itself should prove sufficient in 99% of cases but in extreme circumstances I can give out the passcode which provides an additional two layers of verification (the validity of the password itself, and the photographic identity verification)
Of course that could still be spoofed if someone managed to replace all instances of my verification image, and then made a fake drivers license with my name on it and took a picture of that. But if that ever did happen I actually have a final layer of protection which I won't tell anyone about until I can figure out a way to re-tell it without rendering it worthless.
Online PGP Signature: This is an online javascript-based tool which allows you to sign messages using your PGP private key.
Given a private PGP key to a website that isn't even SSL encrypted is the antithesis of good encryption behavior.
Yeah... Ummmm..... There's a lot wrong with this.
Don't get me wrong. I appreciate the need for constant vigilance, but this type of knee-jerk reaction is what prevents the wider scale adoption of good crypto practices.
Edit- for posterity's sake: I accidentally down voted your post when I meant to upvote it. I wasn't just being snide when I said "I appreciate the need for constant vigilance", and it definitely resulted in a good discussion. I updated my vote.
Actually, there is still a small danger to executing this via a non-SSL encrypted web site, even if I trust that you have no malicious intent, your site has not been compromised and the script runs client-side. The danger is a man-in-the-middle attack, in which an attacker intercepts my http request for the script and replaces your script (in the response) with a version that captures my private key and sends it to a server controlled by the attacker.
I realize that most browsers won't let client-side javascript send requests to hosts other than the original host from which the javascript was loaded, but that fact won't solve the issue; the modified version of the script could send the private key to a URL apparently on your host, and the man-in-the middle daemon could intercept the request and send it to the attacker's host.
Such an obvious and easy to exploit vulnerability has existed for 20ish years, undiscovered/unexposed until one person on LW pointed it out?
It's not a vulnerability. I trust gnupg not to leak my private key, not the OpenPGP standard. I also trust gnupg not to delete all the files on my hard disk, etc. There's a difference between trusting software to securely implement a standard and trusting the standard itself.
For an even simpler "vulnerability" in OpenPGP look up section 13.1.1 in RFC4880; encoding a message before signing. Just replace the pseudo-random padding with bits from the private key. Decoding (section 13.1.2) does not make any requirements on the content of PS.
These sound like great tools. Thanks for making them available.
On a meta level I don't mind if members of the community promote their own work here if it's something that other community members will find useful. I'll also note that these seem lik tricky enouph things that they could also have been mentioned in the bragging thread when you finished them.
The "decoy" pictures are indistinguishable from any other picture on your or your recipients' camera rolls, and unless you have the passphrase, then the original image is thoroughly inaccessible.
What does "indistinguishable" mean in that sentence? Do you claim that a skilled attacker can't know that there metadata added?
For grins:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256
Information security is a pretty big passion of mine; I don't think someone needs to have "something to hide" in order to make use of digital signing, encryption, etc. Another passion of mine is making things easier for other people to do. I've written a couple of tools that I think can be useful for the LW crowd.
Online PGP Signature: This is an online javascript-based tool which allows you to sign messages using your PGP private key. I love the idea of PGP-signed messages (I remember someo...
If you are passionate about computer security, you know the standard advice to NOT use unaudited tools from unknown sources.
"Just look at my code" is not a good answer since people who can usefully look at your code already have a large variety of well-known tools at their disposal. Your target is "normal" people and to them your code is gibberish anyway.
This is not a program I wrote but while we're posting things I have a guide to setting up Automator on a mac to send out an email on login on my blog.
Information security is a pretty big passion of mine; I don't think someone needs to have "something to hide" in order to make use of digital signing, encryption, etc. Another passion of mine is making things easier for other people to do. I've written a couple of tools that I think can be useful for the LW crowd.
Online PGP Signature: This is an online javascript-based tool which allows you to sign messages using your PGP private key. I love the idea of PGP-signed messages (I remember someone under the pseudonym "Professor Quirrell" handing out PGP-verified Quirrell points a few years back). The problem is, I had yet to find an easy way to do this that didn't involve downloading command-line based software. So I wrote this tool that uses open-sourced, javascript-based PGP libraries to let you easily sign messages in your browser.
The whole thing is client-side so your private key is never seen by me, but be smart about security. If you don't trust me, that's fine, just don't use the tool. But also remember that you could have a virus, your computer could be monitored, someone could be watching over your shoulder, etc. so please be smart about your security. But hopefully this can be helpful.
Decoy: an iPhone App: I wrote this after "The Fappening", where I was basically appalled at the terrible security practices that pretty much everyone uses when sending pictures back and forth. Decoy uses a combination of steganography and AES encryption to let you send images back and forth without having to sign up for an account or use some outside service that can be hacked or otherwise compromised.
You take the original picture, then you come up with a passphrase, then you take a "decoy" picture. The original picture is converted to base64 image data, which is then AES-encrypted using your passphrase. The resulting cipher text is then encoded into the pixels of the "decoy" picture, which is what gets saved on your phone and sent out. The "decoy" pictures are indistinguishable from any other picture on your or your recipients' camera rolls, and unless you have the passphrase, then the original image is thoroughly inaccessible.
If your phone is lost, hacked, stolen, or (more benignly) someone happens to be looking through pictures on your phone, all anyone will see are the "decoy" pictures. Without the password, those pictures are worthless. Although the app is primarily branded for, *ahem*, "personal use", there are plenty of other ways to use it. For example, my wife and I use it for things like sending pictures of sensitive physical documents like credit cards, birth certificates, social security cards, etc.
(full disclosure: although Decoy is free, it is ad-supported so I do financially benefit from people using the app. But on the bright side I'm an avowed rationalist and if I make a quajillion dollars with this app I will spend the vast majority of it on LW-friendly causes!)