Random: I really like how simple the Google Authenticator's TOTP algorithm is: h... | Hacker News

Hacker Newsnew | past | comments | ask | show | jobs | submit

IgorPartola on March 17, 2014 | parent | context | favorite | on: Two Factor Auth List

Random: I really like how simple the Google Authenticator's TOTP algorithm is: https://github.com/tadeck/onetimepass/blob/master/onetimepas...

It's only a few lines of code and other than having sync'ed clocks does not require any other running services. At one point I implemented it as a second factor for my most important servers that I ssh to so that my IP would be unlocked for 45 minutes after the initial connection.

stavros on March 17, 2014 [–]

Nitpick: It's not Google's, it's an open standard (OATH): http://tools.ietf.org/html/rfc6238

There's also HOTP.

IgorPartola on March 17, 2014 | [–]

You are right, I should have elaborated. Just like most people, I first learned about it from using the Google Authenticator app.

stavros on March 17, 2014 | | [–]

Sure, I'm just clarifying that it's a standard (and thus awesome).

Consider applying for YC's Fall 2026 batch! Applications are open till July 27.
Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact