When we store confidential information in our database, we encrypt it using AES. In addition, when customers install our product, they protect their machines using a firewall.
Should we use different encryption keys (passphrases) for different customers? What would be the benefits and/or drawbacks?
We have Web UI system that access via a browser. The encryption keys (passphrases) are stored on the server side. Web client to not have access to encryption keys (passphrases). Example of the confidential information: LDAP Bind DN password. This password is used by server side when a user authenticated against LDAP.
Therefore all user should be able to use the encryption keys (passphrases) during LDAP authentication but no one need to read it (in fact nobody read it)