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  • Hacker News
  • =0 I stumbled across this post and was thinking that it's interesting to see this topic trending now, since I've done a lot of work on it in the past. Then I clicked through and realized the author is linking to some of my stuff! What a blast from the past.

    Anyhow, there are way smarter people than myself who have covered this topic extensively over the years, but I still think that, even in 2026, JWTs are the wrong tools for web auth. They're fine to use for service-to-service stuff, but if you have the option, just use PASETO -- it solves a lot of the issues!

  • JWTs are awesome but they are are being overused by people. People use them in web, on mobile and everywhere in between. Places where cookie or bearer token auth has already solved the problems. JWTs strength is that it can be verified independently without real-time coordination between services. So a service can issue a JWT with auth scopes to a user. The user can take the JWT to any other service and if that service trusts the signer, it'll allow the user access and also get basic user info from the token itself. The service doesn't need to make an API call to the issuing service or even know if/where it exists. That is where JWT is really powerful.

    For web/mobile auth where same server issues the JWT and same server verifies it, it makes no sense. JWTs cannot be invalidated. If a user loses some permission or account gets disabled, JWT will still be valid until its expiration time. Servers must either make DB calls to verify the user is still active or be fine with deactivated users having access for a while after account is disabled. This completely defeats the purpose and bearer tokens work perfectly for this use case.

    JWTs should _almost_ never be used in client side auth. Client should send regular cookies and bearer tokens. The auth server can internally generate a short lived JWT and inject it into requests before they get routed to various services internally so those services don't need to query DB every time to verify the user.

  • JWTs are fine, seems a bit sensationalist title...

    Some nice topics to talk about instead:

    - When to use an encrypted value (and symmetric or asymmetric), vs. a random (but secret) value, vs. a signed value (readable but not tamperable)

    - Where to put these values (memory, localStorage, cookies)

    - How to make sure these values don't last forever, and whether you need to be able to revoke them (make them invalid before their natural expiration timestamp)

  • Okay, so hack into a site that uses JWTs for login, if it’s so insecure we should be seeing loads of attacks against them right? Stolen tokens everywhere being used to impersonate people and other things. For example I believe ChatGPT is using Auth0 which uses JWTs, so you can hack this insecure token system? Should be easy right given the extremity of the warning that JWT is the big problem here.
  • In sessions vs. JWT revocation lists, there is an argument in favor of JWT revocation lists. JWTs have a limited expiry timestamp, so you only ever need to maintain a revocation list for tokens not expired yet. Given that you probably only have a fraction of JWTs revoked compare to valid JWTs in circulation, you only need to query a very small dataset for each request.

    When using sessions, your list of valid sessions is probably orders of magnitudes higher that the revocation list - thus the data lookup costs and the storage cost of that statefulness is higher.

    Plus, the article mentions JWTs are stateless but that is usually not true. You mostly not only validate the JWT, but also obtain a matching identity object (i.e. user details) for each request to see if the user is still enabled/authorized to do whatever he does. You can leverage stuff such as per-user revocation lists, or a minimum_issued_at that will validate any JWT iat field. This allows the "Logout from all devices" pattern, where that action will simply set a user's minimum_issued_at field to $NOW. All previous tokens will thus be revoked, without individuall revocation list checks.

  • This links to some other blog post for the bulk of it's 'why', and that blog post mostly seems to be annoyed about "You cannot invalidate individual JWT tokens". Which every time I've implemented, the general guideline is to check for invalidated nonces somewhere. Which resolves that random blog posts second point too.

    >The JWT specification itself is not trusted by security experts.

    This feels like it needs more evidence than just one blog post. And that blog post seems to just largely blame bad implementations? Something that will plague any standard.

    Overall, I don't know what I expected clicking a random gist link.

  • JWTs are insecure... even when using trusted, rsa/ppk based signing methods? not shared secrets.

    JWTs are too long lived... Nothing is stopping you from limiting the JWT lifetime and having a refresh model against an authentication authority... I mean, even if you use cookie based sessions, you're storing somewhere... you can have a jwt valid for 5-15min. 15minutes is roughly the cache timing for many authorization systems including Entra... and even a 5min token with a refresh system can be used fine from a browser.

    Lastly, I prefer to have identity/auth separated from the application/api services... it externalizes context and JWT per request is easier to deal with than some shared cache/state system that may intermittently fail as opposed to a signed token that you can verify the signature against known authorities.

  • Necessary qualifier: for browser-based user sessions.

    Plenty of good uses for JWTs for service-to-service communication.

    edit: I read some of the linked stuff, e.g. https://paragonie.com/blog/2017/03/jwt-json-web-tokens-is-ba... . Please, if JWTs are such a horrifically insecure standard, go ahead and publish your means for hacking AWS STS's AssumeRoleWithWebIdentity , or don't publish and just exploit it by launching cryptominers in every Fortune 500 production AWS account. Let me know when you inevitably succeed, because JWTs are so insecure, right? /sarcasm

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