Secure Coms

83 readers

1 users here now

This is a community for enthusiest who love to ponder new ways for Alice to communicate with Bob in a world where global passive adversarys probably record every bit that ever crosses the wire.

Discuss cryptography, secure key exchange, private messangers, radios, encoding, networking tools, authentication mechanisms and anything relevant to coming up for ways to Alice to get a message to Bob.

founded 1 month ago

MODERATORS

cm0002@programming.dev

Nifty local webserver ultity to convert a image to base64 then encrypt with AES-256 GCM (infosec.pub)

submitted 1 week ago by cm0002@futurology.today to c/securecoms@programming.dev

6 comments fedilink hide all child comments

This application is a local only web instance that can be spun up in termux.

Here is the source code.

Its configured to be a local only service utility although it wouldn't take much to point this to the web.

After picking a image, you can configure the compression. I found large image files basically require the compression. There is a limit to how much text you can copy...its very large...but the higher quality the image the longer this string of text will be, so you may need to lower the quality if you run into problems.

You can either copy the text directly, or download a blob as the .txt file for transport.

Termux side server manager.

Encrypted blob example.

top 6 comments

sorted by: hot top controversial new old

[–] TootSweet@lemmy.world 4 points 1 week ago (1 children)

In binary mode, why are we base64-encoding the raw JPEG data before encrypting? It ought to be quite a bit more space efficient if no base64-encoding is done before encrypting.

[–] hereforawhile@programming.dev 3 points 1 week ago* (last edited 1 week ago) (1 children)

Your right. That isn't doing anything except effectively lowering image quality potential since it's just adding extra data for no reason.

I should update so it's only running base64 after...that's just so it's easily copypastable

[–] TootSweet@lemmy.world 3 points 1 week ago* (last edited 1 week ago) (1 children)

I think misconceptions about base64 are surprisingly common. Both the misconception that it adds security (people confusing it with an encryption algorithm) and the misconception that it reduces size (like compression does).

HTTP Basic auth, for instance, uses base64, and I think people see that and think it's for security. I guess it kinda is in that it's a pretty weak mitigation against shoulder surfing. But people see that and think base64 is encryption. I've unironically heard coworkers use the term "base64 encryption", which always makes me wince.

And I've definitely corrected coworkers in the past who thought that base64 would just magically make binary data smaller. It does make binary data smaller than base16 encoding does (while still letting you put binary data in places not meant for binary data -- URLs, for instance). Maybe that's part of where people's misconception about base64 reducing sizes comes from?

Who knows. Who knows.

Edit: Oh! You're the author. I didn't catch that until after I typed up this reply since you aren't the OP for this thread.

[–] hereforawhile@programming.dev 3 points 1 week ago

I'm definitely in that category of misconception where I would assume adding extra bits of information before encryption may help the strength of the encryption somehow but it really doesn't at all I guess.

Yeah I don't know who the poster is, but the original is posted on the lemmy.ml instance. I think it's a bot maybe attempting to federate non federated content or something? I don't really understand how it ends up on the programming.dev instance.

[–] refalo@programming.dev 4 points 1 week ago* (last edited 1 week ago) (1 children)

What is the usecase for something like this?

[–] hereforawhile@programming.dev 2 points 1 week ago

It for that limited scenario where you want to send a image but all you can send it text