https://openauthentication.org (pas de news depuis 2012)

Specifications:

• HOTP: An HMAC-Based OTP Algorithm (RFC 4226)
• TOTP: Time-based One-time Password Algorithm (RFC 6238)
• OCRA: OATH Challenge/Response Algorithms Specification (RFC 6287)

multiOTP open source is a GNU LGPL implementation of a strong two-factor authentication PHP class and is OATH certified for HOTP/TOTP (dernière version 5.9.6.5 du 2023-07-07)