SMS 2FA Insecurity

This cluster focuses on criticisms of SMS-based two-factor authentication (2FA) due to vulnerabilities like SIM swapping and SS7 attacks, with recommendations for secure alternatives such as TOTP or hardware keys.

📉 Falling 0.2x Security
4,983
Comments
18
Years Active
5
Top Authors
#2680
Topic ID

Activity Over Time

2009
8
2010
11
2011
39
2012
103
2013
94
2014
131
2015
82
2016
228
2017
318
2018
307
2019
467
2020
408
2021
692
2022
697
2023
578
2024
535
2025
275
2026
10

Keywords

e.g IT US TOTP OTP SMS arstechnica.com HN SIM U2F sms 2fa totp secure phone sim authentication password otp mobile

Sample Comments

vmception Jun 16, 2020 View on HN

Why are you using SMS 2FA?

_Algernon_ Aug 6, 2022 View on HN

You shouldn't be using sms as 2fa anyways. It's barely better than no 2fa at all. Use an authenticator app.

exabrial Apr 7, 2020 View on HN

Please stop supporting sms for 2FA. It's not better than nothing, it's worse than nothing. Given the extent of technology workers on hacker news please work to remove this antipattern from your products.

ivanjermakov Aug 8, 2025 View on HN

Related: SMS 2FA is not secure https://news.ycombinator.com/item?id=27447206

sand500 Oct 5, 2022 View on HN

SMS 2FA is not secure. Lots of HN posts about it:https://hn.algolia.com/?q=sms+2fa

sammy2255 Sep 12, 2023 View on HN

Ironically SMS 2fa is less safer than just using a password

sha666sum Oct 17, 2019 View on HN

SMS 2FA is better than nothing if, and only if, you don't allow password resetting by owning the SMS.

tapoxi Feb 26, 2021 View on HN

Don't use SMS as 2FA, it's insecure. TOTP is a much better solution.

stephenr Aug 1, 2017 View on HN

I think you need to re-visit your SMS support decision. SMS for 2FA is not secure, at all.

ThePowerOfFuet Jun 26, 2021 View on HN

Why are you using SMS 2FA anyway?