The most popular alternative is andOTP, which is both free and Open Source. If that doesn't suit you, our users have ranked 11 alternatives to OpenSK so hopefully you can find a suitable replacement. Other interesting OpenSK alternatives are Google Authenticator (Free), YubiKey (Paid), SoloKeys (Paid, Open Source) and Nitrokey (Free, Open Source).
- It implements Time-based One-time Passwords (TOTP) and HMAC-Based One-Time Passwords (HOTP). Simply scan the QR code and login with the generated 6-digit code.
- Google Authenticator generates 2-step verification codes on your phone.
- The YubiKey is a one-time password device for secure login with two-factor authentication
- Solo is an open source security key, and you can get one at solokeys.com.
- Email Encryption. Encrypt your emails with GnuPG, OpenPGP, S/MIME or your favourite email client. Keep your secret keys secure on your Nitrokey.
- Krypton implements the standardized FIDO Universal 2nd Factor (U2F) protocol to provide secure, un-phishable two-factor authentication on the web, using just your phone.
- This app is created for use with the YubiKey NFC and NEO to copy One-time-passwords (OTPs) from a YubiKey into the iOS clipboard.
- 2FAS Authenticator is a simple and free application for Two Factor Authentication (2FA Authentication) which generates Time-based One-time Passwords (TOTP) and PUSH...
- A secure and open source 2 factor authentication token. Designed to be affordable and reliable.
- A simple application for multi-factor authentication, written in HTML using jQuery Mobile, jsSHA, LocalStorage and Application Cache.