Nowadays it's probably 5C, or 5 if you need USB-A connector. An added benefit of Yubikey backed keys is touch to use so that you need to physically touch the t

Nowadays it's probably 5C, or 5 if you need USB-A connector. An added benefit of Yubikey backed keys is touch to use so that you need to physically touch the token to use the key. A critical matter when using ForwardAgent! [0]: https://developers.yubico.com/PGP/Card_edit.html https://developers.yubico.com/PGP/Card_edit.html