Talk:Public-key cryptography

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Trim and tidy[edit]

Have just done a tidy-up of the intro. The rest of the article is in dire need of the same. - Snori (talk) 19:14, 26 December 2018 (UTC)[reply]

Have now done a fairly brutal edit of the body. I would suggest that the most important element to any further changes are: Keeping/building a good structure of sections; Tight wording; Good citations to back the text. - Snori (talk) 20:35, 26 December 2018 (UTC)[reply]

I believe the introduction needs another clarification. imo it confuses the objective (mathematical) fact that asymmetric cryptography allows for two unrelated keys to encrypt and decrypt any string / message with the convention that one of those keys is considered public and the other private for most uses. Your comments welcome.--BBird (talk) 13:47, 7 August 2019 (UTC)[reply]

You’re absolutely right about the confusion of the two objective facts in the lead, but the problems with this article go further than that. I came to it hoping to find an explanation about how it is that one key (namely, the private key) can decrypt something that was encrypted using another key (namely, the public one), but there is nothing in the entire article that explains this.

The principle seems to imply that the two keys are related, but... how, exactly? In fact, the first bullet of the Description section does (somewhat) confirm a relation by stating that the private key must “match” the public one that was used for the encryption. Again: how exactly do they match? 74.58.147.69 (talk) 20:17, 27 August 2019 (UTC)[reply]

References[edit]

Reverted vandalism[edit]

I have just reverted a spate of changes by @2402:3a80:19f8:c3dc::2 which had seemingly randomly copy-pasted chunks of text of the article into different sections. As far as I can tell there were no meaningful contributions made with any of these edits – just nuisance text. I think I got them all. Phidica (talk) 02:17, 9 December 2022 (UTC)[reply]

@Phidica It looks like you got it all. I wasn't sure what was going on with this contribution. Thanks for evaluating it. ~Kvng (talk) 15:24, 12 December 2022 (UTC)[reply]

Diffie Hellman Diagram[edit]

Is the Diffie Hellman Diagram accurate? Im under the impression that the shared secret is obtained by a shared public secret combined with the two private keys. The diagram seems to indicate that the private key of Alice with the public key of Bob is equal to the private key of Bob mixed with the public key of Alice. Epachamo (talk) 23:48, 9 February 2024 (UTC)[reply]

Yes, it is accurate. Alice and Bob's private keys are

a

and

b

, and their public keys are

g^{a}

and

g^{b}

. Alice computes the shared secret by combining her private key

a

with Bob's public key

g^{b}

via

(g^{b})^{a}=g^{ba}=g^{ab}

; Bob computes the shared secret by combining his private key

b

with Alice's public key

g^{a}

via

(g^{a})^{b}=g^{ab}

.

The whole point is that Alice and Bob need only exchange public information over a channel that an adversary may be eavesdropping on, and can still establish a shared secret. If each party had to also learn the other party's private key in advance over some secret channel they'd previously established, it wouldn't have been a revolutionary idea in 1976. Taylor Riastradh Campbell (talk) 11:47, 10 February 2024 (UTC)[reply]