[randomint64]

While it's true that API keys are basically prefix + base32Encode(ID + secret), you will want a few more things to make secure API keys: at least versioning and hashing metadata to avoid confused deputy attacks.

Here is a detailed write-up on how to implement production API keys: https://kerkour.com/api-keys

[9214063141]

Interesting read, I do have some questions though and hope you could answer them:

1. Why do you use the API key ID AND the organization ID, and not just one of them, to prevent the confused deputy problem?

2. Why is not necessary to use something like Argon2id for hashing? You say "our secret is already cryptograhically-secure", but what does this mean exactly? Is it due to the fact that the secret is already very high entropy and cracking it, even if we use much faster hash functions like the ones mentioned in your article, it would practically not be possible even PQ with highly parallelized hardware?

Anyways, very interesting read, thank you!

[jeremyloy_wt]

I don’t understand your explanation on mitigating the confused deputy. If the attacker has access to the database, can’t they just read the IDs for the target row they are overriding first so they can generate the correct hash?

[randomint64]

The attack would be like: attacker has read/write access to the database but not to the code of the backend service. Attacker swaps the hash of a targeted API key with the hash of their own API key. Attacker has now access to the resources of the targeted organization when using their own API key.

[vjay15]

Thank you! I will definitely look into it!