We have tried this for a while and the following reasons made us kill it: 1. Email delivery latency: depending on the service you use, the time it takes to deliver emails to the user can vary. Worst case I encountered was up to 20 minutes delay when there were issues with Mailgun. 2. Usability: you have to leave your current app and switch to your mail client. You may be on a device where you don't have a mail client…
From a user standpoint the delivery latency is really what kills it for me. I use one or two websites that still have one-time sign in links and it's always a tossup whether or not I can actually get in within a few minutes. If the email arrives an hour later I've moved on with my life and I can't imagine it is any different for other people.
Ask HN: Why aren't one-time sign in links more popular for authentication?
51–60 of 198 posts
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#52I'm assuming you intend those links to be single-use only and expire automatically, in which case what I'm writing below doesn't apply. Nevertheless, the problem is big enough to be worth repeating and re-repeating: Any link that ends up in a browser address bar should be treated as public. And no, it doesn't matter if you use HTTPS. Ways to leak it are many, but the gist is that it's treated as "meta-data" and, righ…
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#53Everyone has an HSM in their pocket these days. The fact that we are having these discussions at all is ridiculous.
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#54Oh, this is so terrible. I hate this approach with a passion. E-mail is NOT INSTANTANEOUS. It was never meant to be. It happens to arrive quickly for most people most of the time, but you should never, ever, base a service on that. Many systems have greylisting in place: a new sender gets a 4xx reply, and is allowed through only on subsequent retries after a pre-set time period. This is often as much as 30-60 minutes…
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#55Wonder what the impact of that has on both of them?
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#56From a cryptographic perspective, when dealing with authentication the different methods fall in one of the different categories: 1) Something you know (e.g. a password) 2) Something you have (e.g. a token) 3) Something you are (usually biometric authrentication, like your fingerprint, a retina scan...) Real OTPs fall in the second category, because you have some device/application that is able to generate the same O…
I've always considered them to be more like user names, albeit with a larger entropy than your average user string.
Completely agree with your points though. Particularly with regards to OTP. I'd further expand on that and say hosting your TOTP codes in the same password management tool as your passwords themselves (as some tools are now offering) is also really bad idea.
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#57We have tried this for a while and the following reasons made us kill it: 1. Email delivery latency: depending on the service you use, the time it takes to deliver emails to the user can vary. Worst case I encountered was up to 20 minutes delay when there were issues with Mailgun. 2. Usability: you have to leave your current app and switch to your mail client. You may be on a device where you don't have a mail client…
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#58Oh, this is so terrible. I hate this approach with a passion. E-mail is NOT INSTANTANEOUS. It was never meant to be. It happens to arrive quickly for most people most of the time, but you should never, ever, base a service on that. Many systems have greylisting in place: a new sender gets a 4xx reply, and is allowed through only on subsequent retries after a pre-set time period. This is often as much as 30-60 minutes…
Email has been nearly instantaneous for me for the past decade or so. Either it arrives in a 30 second window, or never. Usually 2-5 seconds.
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#59Earlier quoted context omitted.
From a user standpoint the delivery latency is really what kills it for me. I use one or two websites that still have one-time sign in links and it's always a tossup whether or not I can actually get in within a few minutes. If the email arrives an hour later I've moved on with my life and I can't imagine it is any different for other people.
I've experienced that too.
Re: Ask HN: Why aren't one-time sign in links more popular for authentication?
#60Email is not a secure delivery mechanism. Everyone has an HSM in their pocket these days. The fact that we are having these discussions at all is ridiculous.
If you refer to the typical smartphone, it's an HSM without the Security, and also it's not truly Hardware.