Nitrokey is described as 'USB security device for encryption, digital signing, and secure login, featuring secret key storage, user PIN, tamper-proof smart card, and open source design' and is a Authenticator in the security & privacy category. There are more than 10 alternatives to Nitrokey for a variety of platforms, including Android, iPhone, iPad, Mac and Linux apps. The best Nitrokey alternative is 2FA Authenticator (2FAS), which is both free and Open Source. Other great apps like Nitrokey are Authy, YubiKey, OVault and OnlyKey.
2FAS Authenticator is a simple and free application for Two Factor Authentication (2FA Authentication) which generates Time-based One-time Passwords (TOTP) and PUSH authentication*.
Manage two-factor authentication seamlessly across various platforms with secure cloud backups and offline access. From Gmail to LastPass, enhance security effortlessly. Sync multiple devices securely and protect sensitive data with robust encryption.
The multi-protocol security key offers the highest assurance, protecting devices with passwordless workflows and strong 2FA against phishing. It plugs into computers, tablets, and mobile devices, integrates PIN or biometric for identity verification, and reduces helpdesk costs.
OVault is a super simple OTP app that lets you view and manage OTPs for all your accounts. Set up OTPs by scanning QR codes with your devices Camera App, or by manually providing the OTP secret to the app.
OnlyKey is an open source alternative to YubiKey. OnlyKey natively supports: a hardware password manager, multiple two-factor methods (FIDO2, TOTP, and Yubico® OTP), passwordless SSH login, and OpenPGP.
Sign in is easy, convenient, and secure when you use Microsoft Authenticator. Use your phone, not your password, to log into your Microsoft account. You simply have to enter your username, then approve the notification sent to your phone.
OTP authenticator app for managing your 2FA / OTP codes on iPhone, iPad, Mac and Apple Watch.
Google Titan Security Keys offer two-factor authentication to prevent phishing and man-in-the-middle attacks. They support FIDO standards and come in USB-A, USB-C, and Bluetooth formats, ensuring compatibility with various devices and services.
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.
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Its among the only open source Apps in this list. For security and Privacy, Open source is always important, as anyone can look into the code. When there is a vulnerability in the code, it doesnt depend on a company to solve the issue.