Think about it, the key analogy is just terrible. In the origin domain, losing a key is always bad, and making a key available to all is a non sequitur.

It's not like non-technical people understand asymmetric cryptography. Or even technical people, for that matter.

Maybe we should refer to the public key as an address, and the private key is just a password again. You can send stuff, securely, to an address. And you can verify the sender when you have their address (ie check the signature).

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fc417fc802 4 hours ago | parent | next [-]

The key analogy is perfect for the private key and for symmetric keys. Publishing those is always bad and means you need to rekey immediately just like losing a traditional physical key to a secure building would.

The public counterpart is tricky to name but I think attaching "public" to it makes the intended usage plenty clear. There isn't really a physical counterpart unless you consider maybe those machines that check for counterfeit cash but even that's not a great fit because the pubkey is simultaneously analogous to a lock box.

	▲	tialaramex 21 minutes ago \| parent [-]
		Not quite. The analogy works for secret keys (what you're calling "symmetric keys") but a private key is unlike real world key analogies because as you'll quickly discover if you deploy real world keys in a high security environment people can examine the lock to figure out the correct key. The whole point of private keys is that this cannot work in a public key system. That step does not exist. It is true that publishing your private key is bad but you'd hope the name makes that pretty clear. Despite the way I remember (U2's "The Fly" lyrics, "A secret is something that you tell one other person, so I'm telling you, child") people generally do not understand that the whole point of secrets is that at least two parties know, which means you might always be betrayed by somebody you think is keeping your secret. For a private key it's easy, don't tell anybody, nobody knows, you can't be betrayed, done. For example Hacker News learns my password to this web site every single time I sign in because that's just a secret. We've known how to do better for decades but only a handful of systems I use (e.g. Google) do so and all of them have a "traditional" password option which is like discovering your aeroplane still has a smoking section in 2026.

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SilasX 3 hours ago | parent | prev | next [-]

Yeah, that always bothered me about the terminology. My fix would be to call it a lock -- everyone understands that you can share those and it doesn't make them any easier to open.

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morsch 3 hours ago | parent [-]

That analogy works for encryption but doesn't really work for signature verification

	▲	snmx999 21 minutes ago \| parent [-]
		Maybe we should not use analogies? Just call them secret-text and public-text.

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fragmede 4 hours ago | parent | prev [-]

Or how about we call it the lock. There's the (private) key, and it fits the lock (public key). You can pass the lock around, but you need the (private) key to be useful.

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danw1979 3 hours ago | parent [-]

I dunno if that works or is any less confusing, to be honest.

I don’t think there’s any process or entity in the physical world that is reasonably familiar to most people that is even remotely suitable as an analogy to public key cryptography.

	▲	tialaramex 13 minutes ago \| parent [-]
		I think this is worth highlighting. Public Key Cryptography is a surprising idea. Like Computation, if you'd told a 19th century mathematician about this, they might buy it as a concept but deem it unlikely to ever happen in practice or be of any significance, in the 20th century these were both realised and caused a massive change to our society. These are not analogs to things ordinary people had already seen. For Computation we just got used to it being everywhere and so we don't need to explain it so much.