Identify the Tor relay used for data transmission in an encrypted format, receiving the client's data from the entry relay, and passing the client's data to the exit relay.

The middle relay plays a crucial role in the Tor network by facilitating the secure transmission of data between the entry relay and the exit relay. When a client connects to the Tor network, their data first passes through the entry relay, which encrypts and forwards it to the middle relay. The middle relay does not decrypt the data; instead, it acts as an intermediary that helps to obscure the client's original IP address by only knowing the previous and next hops in the circuit.

Once the middle relay receives the encrypted data from the entry relay, it forwards this data onward to the exit relay, which is the last relay that sends the data out of the Tor network to the wider internet. The middle relay maintains the encryption and anonymity of the data during this transmission, ensuring that the information is securely passed along without exposing the identity or the location of the client.

In contrast, the entry relay is responsible for receiving the initial data from the client and begins the process of encryption, while the exit relay is tasked with delivering the final data to its destination outside the Tor network and decrypting it, revealing the contents. The guard relay is a specific type of entry relay designed to provide an additional layer of security for Tor users. Therefore, the middle relay is essential for maintaining