If you want to SSH into a host without a password, follow this short guide.
Note that this will be a one-way transaction; you can only go from Host A to Host B, unless of course you follow this procedure and swap the devices.
First, generate a pair of authentication keys on Host A without using a password:
ssh-keygen -t rsa
…next, still on Host A, use SSH to create a directory, which may already exist, on Host B. You must use the password this time:
ssh foo@b mkdir -p ~/.ssh
…next, and again on Host A, append the key from Host A you generated to the appropriate file on Host B:
cat ~/.ssh/id_rsa.pub | ssh foo@b 'cat >> .ssh/authorized_keys'
At this point, you should be able to SSH from Host A as the example user ‘foo’ (or whatever username you used) to Host B.