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# Since this is a critical file, back it up first.
sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.2011-02-12.v0.0.tinpham_about_to_disable_password_auth.bck
# Load the file in your favourite editor.
sudo vi /etc/ssh/sshd_config

Adjust We can modify sshd_config quickly using sed,

sudo sed -i 's/#PasswordAuthentication yes/PasswordAuthentication no/g' /etc/ssh/sshd_config

Changes the following,

# Change to no to disable tunnelled clear text passwords
#PasswordAuthentication yes

Remove the comment Uncomment and change yes to no. It should look like this,

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The Permission denied indicates that password authentication is now disabled.

Key Compromise

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Strategies

Reusing Public Keys Across Machines

You can actually reuse public keys across machines. With this approach, you only need to keep track of one private key per user. Of course, this also means if your private key is compromised all your systems are accessible with the one key.

Key Compromise

• ... revoking keys
• ... strategies for centralizing key management and then also pitfalls
• ... is it possible to force password protected private keys

Resources

http://www.ibm.com/developerworks/library/l-keyc.html - pretty good article, I think I can improve it, shorter, clearly show when running on client or server.

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