Master keys are your Organization's public keys, used by Canary to encrypt all outgoing emails sent by your users, in addition to the email recipients’ public keys.
Also, Master keys help you decrypt older emails without the need of the secret key of your Organization's ex-employee.
1) You can specify your Organization's public keys under Master Keys.
2) You can upload Organization's public keys via Encryption > Master Keys > +.
3) This will ask you to upload the public key file.
