Passphrases can be generated with Diceware or the Ubuntu command 'apg -a 1'.
Encryption, Authentication and Signatures
Encryption, Authentication and Signatures can be developed with GnuPG.
YubiKey - Security USB Device
Yubico have created a USB security key called a YubiKey, used for passwordless authentication, OTP, PAM, RF-ID, etc.
YubiKey OTP authentication test:
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