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Comment by gaius_baltar | Hacker News Reader

This seems to me a fundamentally bad idea: signing commits should be a "long lived" thing, but using an infrastructure designed for easily replaceable authentication (ie: add your pub keys to servers and remove/replace/destroy them at the very minimal suspicion of the private keys being compromised). And all the non-existing certification infrastructure (the article proposes one; we can end up with multiple incompatible signing/certification systems, none of them with the reach of existing OpenPGP). And at last, but not least, putting too many eggs in the same basket.

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It’s better than not signing at all, though, which appears to be the current status quo.

You can also sign with a different key than your “regular” ssh key(s), and as such reduce the chance you’ll have to replace them.

Having said that, key rotation and distribution is obviously better with GPG, and I personally have been using that for years.

Commit signing with S/MIME also works great. The downside is that you have to buy an "email" S/MIME cert from one of the usual cert gatekeepers for a couple dollars, but in return anyone can verify the signatures without exchanging public keys with me (or building a web of trust), and expiration and revocation are solved problems (including verifying signatures made with keys that are now expired, which seems not really supported with SSH keys)

You may want to check out https://github.com/sigstore/gitsign! You can generate ephemeral x509 code signing certs for free using Sigstore.

(disclosure: I'm a maintainer for gitsign)

Wow! This looks like an incredible ecosystem for managing signatures and for verifying the software artifact supply chain.

How is expiration a solved problem? You won't be able to verify commits after the cert expired without additional information because you don't know that the commit timestamp is valid. For code signing you there are timestamping services to solve this but this means that you are now dependent on a central authority which could just host verified hashes without all the crypto mess.

You don't have to reuse your keys. You can have a separate key(s) for signing.

The only reason the article gives for using this over using the signing with GPG keys is that you will have an SSH key already. If you need to create a new key, are there any reasons for going for an SSH key over a GPG key?

Because you are already acustomed to ssh?

I personaly use GPG. However, GPG looks complex and the ergonomics of GnuPG cli is horrible.

So use some GUI?

CLI ergonomic around working with ssh keys and ssh certificates is not great either.

And GPG/PGP at least has some standards around key distribution, web of trust, subkeys, etc.

I use GPG Suite on Mac and even then the ergonomics are confusing. GPG/PGP is just kind of confusing for us not deeply into cryptography.

I looked up the screenshots. The app looks like the most trivial possible UI for basic public key cryptography. Just a basic list of your/other people's keys (pretty much a contact list) and some ways to acquire them.

SSH keys if used in place of GPG would have almost the same UI. It's not the problem of GPG, but of the underlying concepts.

You don't need to be deep into cryptography, just understand some basic concepts from the wikipedia article, or whatnot.

The real reason is: I don't gain any security from signing my own commits, I gain security when other people sign their commits which they are currently not doing.

Therefore, making things easier to set up makes a greater contribution to security than strict, gold-standard security features that nobody adopts.

You don't gain any security if you can't verify the signatures of the others.

Signing with a separate hardware-stored SSH key on a dongle (e.g.: Yubikey/FIDO2) will allow you to have a long-lived key without the risk of compromise.

If you're using a dongle, I expect you'd have your other SSH keys there as well. Is there a security benefit to using a separate SSH key if they all live on the same dongle? I'm having trouble thinking through that. Although, certainly the hardware dongle has security benefits over SSH keys on disk.

Yes -- you can separate identities if you want, and rotating keys means changing a lot less places, so you can compartmentalize your processes.

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