Passkeys: how do they work? No, like, seriously. It’s clear that the industry is increasingly betting on passkeys as a replacement for passwords, a way to use the internet that is both more secure and more user-friendly. But for all that upside, it’s not always clear how we, the normal human users, are supposed to use passkeys. You’re telling me it’s just a thing… that lives on my phone? What if I lose my phone? What if you steal my phone?
Glad this is being discussed. Having worked adjacent to the authentication market, I have mixed feelings about it, though.
There are a few problems with passkeys, but the biggest one is that no matter what, you will always need a fallback. Yes, Apple promises a cloud redundancy so you can still log in even if you lose every device.
But that’s just Apple’s ecosystem. Which, for what its worth, is still evolving. So the passkey itself is phishing-resistant, but humans still aren’t. Fallbacks are always the weakest link, and the first target for bad actors. Email, or sometimes phone and SMS, are especially vulnerable.
Passkeys in their current iteration are “better” than passwords only in that they offload the fallback security to your email provider. Meanwhile, SIM swapping is relatively ready easy for a determined social engineer, and mobile carriers have minimal safeguards against it.
Usability? Great, better than knowledge-only authentication. Security? Not actually that much better as long as a parallel password, email, or SMS can be used as a recovery or fallback mechanism.
I’m not saying passkeys are bad, but I’m tired of the marketing overstating the security of the thing. Yes, it’s much more user-friendly. No one can remember reasonably complex passwords for all 100 of their online accounts. But selling this to the average consumer as a dramatic security upgrade, especially when so many still run passwords in parallel or fall back to exploitable channels, is deceptive at best.
So you really need two independent devices with their own passkeys to back each other up.
Not sure exactly what you’re getting at, but any authentication model must be designed with the assumption that a user can lose all their devices, passkeys included. That’s where fallbacks come into play. Even with Apple’s system, you can recover your keychain through iCloud Keychain escrow, which (according to their help page) uses SMS:
While SIM swaps aren’t super common, they’re not the most difficult attack. Passkeys are strong against direct attacks, for sure. But if I can reset your account using a text message sent to a device I control, is it really that much more secure?
So if you lose access to all of your devices, you’re completely locked out of everything until you’re able to get a new working phone activated on a trusted phone number? The trade-off of inconvenience for security here just doesn’t seem worth it to me.
Depends on the provider in question. While Apple does allow SMS recovery, they also let you designate a trusted contact who can let you in as an alternative. This is obviously more convenient (if you have a friend or family member who can be available when you need them), but the situation with SMS vulnerabilities is still my main gripe.
Is it possible to use some kind of fingerprinting to identify people? It works for marketers, could that idea be used for security?
I am a total noob who is interested, if I come across as uninformed it is because I am.
Totally! Browser and device fingerprinting are commonly used as first-line defenses against ATOs (account takeovers). There are other kinds of fingerprinting, like those that can learn about your installed hardware and drivers. Really, I’m learning about more fingerprinting methods all the time. That said, decisions are usually made based on several different information sources. These include variables like:
There’s even some buzz around “behavioral biometrics” to identify individuals by how they type, but this is still not the sole method of identification. It’s mainly about flagging bots who don’t type like humans. However, learning how an individual types can help you determine if a subsequent visitor is the actual account owner or a bad actor.
In my experience, fingerprinting and adjacent identity proofs are rarely used in isolation. They’re often employed for step-up authentication. That means if something doesn’t match up, you get hit with a 2FA/MFA prompt.
Step-up can be pretty complex if you want it to be, though, with tons of cogs and gears in the background making real-time adjustments. Like you might not even realize you’ve been restricted during a session when you log in to your bank account, but once you try to make a transfer, you’ll get an MFA prompt. That’s the UX people in action, trying to minimize friction while maintaining security.
For me, it is the opposite. I would need passkeys to be like my SSH keys - not dependent on some proprietary software and never touching any cloud. For now I am a little bit afraid lock-in might happen at some point, so I wait until the technology matures enough until I can use KeepassXC for it confidently.
Apple isn’t the only one allowing redundancy, most popular password managers allow you to lose all your devices and still have passkeys securely stored in the cloud. And people who don’t even know that password managers exists, aren’t going to the early adopters of passkeys.
I’d anticipate that most providers will do something similar. I just mentioned Apple because they’ve been pushing their “cloud backup” hard while still using SMS as a fallback.
I’d be interested to hear which provider, if any, has managed to get around the usual (vulnerable) channels for recovery.
The document you linked says it requires a combination of your apple account password plus an SMS text sent to a pre-registered phone number? Seems like a pretty good setup for most people. Also has the alternative of recovery contacts and recovery keys.
It looks like turning on advanced protection would eliminate the SMS method but I am not 100% sure. Then you would need recovery keys or recovery contact.
https://support.apple.com/en-us/102651
My biggest worry in these cases is not that I get locked out, but rather that Apple mangles my keychain. I have a USB CSV of my passwords in my bank safety deposit box. With passkey I am not sure of how I would get a similar backup.
I get what you’re saying, but it’s not about getting locked out. It’s about other people using recovery methods to take over your account. Why would anyone try to break through durable public-key encryption when you can just phish a victim’s email account password?
And it’s not like real-time phishing for 2FA/MFA isn’t widespread—it’s just not automated to the same level as other methods. That said, two- or multi-factor is going to stop 99% of automated hacks. It’s the determined ones that I’m concerned about.
In regards to the Apple thing… Apple passwords can be reset using a recovery email. That means the security of the account leaves Apple’s ecosystem and relies on the email provider. So, if I’m a cybercriminal determined to hack your account, I start there.
Then, if you’ve got your keychain all set up, it’s time for a SIM swap. I clone your SIM or convince your mobile carrier to give me a SIM with your number. And even if recovery contacts and keys are alternatives, the use of SMS is problematic. If you really can turn it off, then I’m all for it. But if you can’t be sure, neither can I.
SMS is a very low-security option that is showing its age. It was never intended to be a secure verification method, yet it’s become incredibly popular due to its availability. Unfortuantely, telecom companies are simply not interested in upping their security.
All SIM swap protection is opt-in at this point. Verizon and the gang might wise up considering the lawsuits leveled at them by victims—many of whom lost millions in cryptocurrency due to the carriers’ negligence—but it’s not likely.
The point here isn’t that passkeys are bad for consumers. They’re convenient and about as secure as existing methods. The problem is that they’re being sold on average folks as a security upgrade even though they’re more of a sidegrade. PKI/FIDO already existed before the whole passkeys buzz did, and it had the same limitations. This is mostly just branding and implementation.
If you enable advanced data protection apple cannot recover your account. You need your recovery keys or a designated recovery contact.
The apple doc implies (to me) that a SIM swap only works after you authenticate on an apple device (e.g. using your password) even without advanced data protection. I have never tested that.
You can use the long process (many days) to recover an account assuming you haven’t enabled advanced data protection. I’m okay with that as it is perfect for my grandparents (I had an older relative who got their account back through this method).
I get that you could SIM swap to recover other accounts (not Apple) if they have SMS as a recovery method. That sucks and it really sucks for people who don’t get that an email or SMS recovery can be a giant hole in security.
Gotcha, point taken. Ultimately, I think there needs to be a better identity proofing process overall. But that may rely on a total infrastructure overhaul, which seems unlikely.