SSH key setup using putty

[cctech]

I am in charge of distribution of Adtran 3140's in our company and I am trying to secure the router form all sides. I am trying to setup SSH pub and private key using putty but when I input the key into the adtran I get %input has invalid format. Anyone doing the same and have an idea?

Thanks

[BradR]

CCTECH, were you following the guide below? One thing that could be causing the error is the size, we support keys up to 2048 bits.

https://supportcommunity.adtran.com/jmaxz83287/attachments/jmaxz83287/nv-aos/412/1/Configuring%20SSH...

[cctech]

I have that documentation and have gone through it several times. I think it might be something to do with putty and the only thing that documentation has is for Linux. It references documentation for putty but I am unable to find any documentation for putty.