Question: I need to use another computer to access my ssh server. This is because a recently implemented vpn at my university doesn't work on my current computer and I have lost access to the server. 

I ssh via encrypted ssh keys. Can I copy these keys to the new computer (on which the vpn works). I tried copying the `id_rsa` and `id_rsa.pub` files in the `~/.ssh` folder but it doesn't recognize the keys and there is no prompt to input a password to decrypt the keys. 

EDIT: I can't access the server to generate a new key pair for the new computer and am out of the country so can't physically access it. 

Thanks.

Answer: 
Check the permissions and ownership of your private key file. From [the manual](http://manpages.ubuntu.com/manpages/precise/en/man1/ssh.1.html),

> 
> These files contain sensitive data and should be readable by the user but not accessible by others (read/write/execute). ssh will simply ignore a private key file if it is accessible by others.
> 
> 
> 

Typically the key files should look like this,

```
$ ls -l ~/.ssh/id_rsa*
-rw------- 1 benj benj 1766 Jun 22  2011 .ssh/id_rsa
-rw-r--r-- 1 benj benj  388 Jun 22  2011 .ssh/id_rsa.pub

```

which you can enforce via:

```
$ chown benj:benj ~/.ssh/id_rsa*
$ chmod 600 ~/.ssh/id_rsa
$ chmod 644 ~/.ssh/id_rsa.pub

```
Try running `ssh-add` before you SSH into the server - you should then be prompted for the password and then subsequent `ssh` connects can use your private key.

The `ssh-add` command adds the keys to the key agent.