Yubico Forum

Hi,

I've been trying to configure my Yubikeys in challenge-response mode as per Yubico's instructions for enabling Yubikey Logon for Windows. I have setup the Personalisation Tool as per the attached screenshot (secret key displayed for reference only, not in use), and I have the following Yubikeys:

2x Yubikey standard models - one with firmware 2.2.1 and the other with 2.4.1
2x Yubikey NEO models - one with 3.1.2 and the other with 3.4.9 (purchased yesterday)
2x Yubikey 4 models - both with 4.2.8 (both also purchased yesterday)

One thing I noticed is if I then run the challenge-response tester in the Personalisation Tool I seem to get the same response from only 4 of the 6 keys above despite my settings. The two Yubikey 4 models give a different response from the others.

Is this normal or is there something I'm missing?

If the Challenge presented is 0 bytes, the NEO/Standard will respond differently than the 4/Edge. Basically, put nothing into the "Input challenge" field in the Challenge-Response Tester and you will get different results. Enter even a single character into the "Input challenge" field and the response will be the same for all models.

OK that explains it. I just tried them all again after entering "1" into the input challenge field and now they all have the same response.

Thanks for replying.