Methods, systems, and computer readable media for testing a system under test (SUT). A method includes sending a first test packet to the SUT over a communication link. The first test packet is associated with a layer 2 secure channel that is bound to an emulated network device. The method includes receiving a second test packet from the SUT over the communication link. The second test packet includes an unencrypted portion and an encrypted portion. The method includes forming a test identifier that uniquely identifies the layer 2 secure channel and the emulated network device using a subset of bits from a secure channel identifier in the unencrypted portion of the second test packet. The method includes decrypting the encrypted portion of the second test packet by finding a security key using the test identifier.