API keys can allow agents to access to the IBM UrbanCode Deploy server. Without the correct API key, the server and an agent cannot exchange messages. The server rejects messages that purport to be from the agent if the messages are not encrypted with the key. Likewise, the agent rejects messages that purport to be from the server if the messages are not encrypted with the key. Finally, without the key, no one can read intercepted messages between the server and agent.