To add security to SSH-keys from Man-in-middle-attacks

Question

I would like to get Mobile-phone verification or something else besides the SSH-key verification.

How can you add defence to the SSH-keys?

What do you mean that someone is spoofing you? – Michael Hampton Feb 09 '14 at 07:54 — Michael Hampton, Feb 09 '14 at 07:54

user9517 · Accepted Answer · 2014-02-09T08:11:59.830

5

You can use Two Factor Authentication to improve the security of ssh keys (and other authentication methods). I use Duo's two factor authentication. It's free for a limited number of users and is relatively cheap beyond that. It can be installed in a wide variety of OS/Applications etc. There are other 2FA products available.

edited Feb 09 '14 at 08:11

answered Feb 09 '14 at 07:58

user9517

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score 3 · Answer 2 · answered Feb 09 '14 at 08:16

I found that hardware two-factor tokens work well. I chose the yubikey, because it was reasonably inexpensive, had no licensing costs over and above the initial hardware purchase, required no specialist client-side software except a USB port, and I was entirely responsible for key management and distribution; I had to reposit my trust in noone except myself.

You can find a more detailed writeup here, if you want the technical nitty-gritty. (Disclaimer: I have no connection to yubico at all, save as a satisfied customer.)

score 2 · Answer 3 · answered Feb 09 '14 at 07:58

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Maybe adding a one-time passcode authentication PAM (ex. https://code.google.com/p/google-authenticator/) to your system will give you some extra "layer of security".

answered Feb 09 '14 at 07:58

deagh

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To add security to SSH-keys from Man-in-middle-attacks

3 Answers3