WARNING: UNPROTECTED PRIVATE KEY FILE!

Problem:

$ git clone git@git.assembla.com:YOUR_PROJECT.git
Cloning into 'YOUR_PROJECT'...
The authenticity of host 'git.assembla.com (XXX.XXX.XXX.XXX)' can't be established.
RSA key fingerprint is XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX:XX.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'git.assembla.com,XXX.XXX.XXX.XXX' (RSA) to the list of known hosts.
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@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
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Permissions 0755 for '~/.ssh/id_rsa' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
bad permissions: ignore key: ~/.ssh/id_rsa
Permission denied (publickey,keyboard-interactive).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Solution:

$ chmod 600 ~/.ssh/id_rsa
$ chmod 600 ~/.ssh/id_rsa.pub
$ chmod 644 ~/.ssh/known_hosts
$ chmod 755 ~/.ssh