Wiretap Channels with Causal State Information: Strong Secrecy

The coding problem for wiretap channels with causal channel state information available at the encoder and/or the decoder is studied under the strong secrecy criterion. This problem consists of two aspects: one is due to naive wiretap channel coding and the other is due to one-time pad cipher based on the secret key agreement between Alice and Bob using the channel state information. These two aspects are closely related to each other and investigated in details from the viewpoint of achievable rates with strong secrecy. The general wiretap channel with various directions of channel state informations among Alice, Bob and Eve (called the multi-way channel state information) is also studied, which includes the above systems as special cases. We provide a unified view about wiretap channel coding with causal multi-way channel state information. Index Terms wiretap channel, channel state information, causal coding, secret key agreement, secrecy capacity, strong secrecy