Mastodawn

how diffie hellman key exchange works

(with as little math as possible)

@b0rk Nice! You actually need one more fact: an attacker can't be able to, given S o A and S o B, find (S o A) o B.

Of course, if you can find B given S o B, you can do this; however the converse is not true in general (but may be in concrete cases). So in a way, the DH problem is likely easier than the DL problem, and is probably the real fact that needs to be hard.

However, if you were to put that in panel 2, you'd already be giving away too much there... organizing things well is hard to impossible.

Show thread

Julia Evans 1d ago

@divVerent ah yeah good point! do you know an example offhand where you can find (S o A) o B given S o A and S o B? (but not find B given S o B)

Show thread

Samir Parikh

@b0rk @divVerent Not sure what you're asking but might it be like the mixing paint example in the video I linked to?

In that example, Alice and Bob share a common paint color to which they mix their secret color. They share that combination with each other, add their secret color again to arrive at a shared secret key. Horrible explanation on my part which the video does a much better job at.

But I probably am completely misunderstanding your question in which case ignore this!