Multiple access wiretap channel with cribbing

This paper Introduces the discrete memoryless multiple access wiretap channel with noiseless cribbing, where the cribbing may be either causal or strictly causal. We derive lower bounds for secrecy rates for both causal and strictly causal cribbing under either a decode-forward or partial-decode-forward strategy. Our results recover the achievable rate regions of the MAC wiretap and MAC with cribbing, and demonstrate improvement of secrecy rate due to cribbing. An outer bound is presented for this channel under causal cribbing, which also serves as an outer bound for strictly causal case.