To use SSH with Bitbucket, you create an SSH identity. An identity consists of a private and a public key which together are a key pair. The private key resides on your local computer and the public you upload to your Bitbucket account. Once you upload a public key to your account, you can use SSH to connect with repositories you own and repositories owned by others, provided those other owners give your account permissions. By setting up SSH between your local system and the Bitbucket server, your system uses the key pair to automate authentication; you won't need to enter your password each time you interact with your Bitbucket repository.

There are a few important concepts you need when working with SSH identities and Bitbucket

• You cannot reuse an identity's public key across accounts. If you have multiple Bitbucket accounts, you must create multiple identities and upload their corresponding public keys to each individual account.
• You can associate multiple identities with a Bitbucket account. You would create multiple identities for the same account if, for example, you access a repository from a work computer and a home computer. You might create multiple identities if you wanted to execute DVCS actions on a repository with a script - the script would use a public key with an empty passphrase allowing it to run without human intervention.
• RSA (R. Rivest, A. Shamir, L. Adleman are the originators) and digital signature algorithm (DSA) are key encryption algorithms. Bitbucket supports both types of algorithms. You should create identities using whichever encryption method is most comfortable and available to you.