Newman's theorem states that we can take any public-coin communication protocol and convert it into one that uses only private randomness with only a little increase in communication complexity. We consider a reversed scenario in the context of information complexity: can we take a protocol that uses private randomness and convert it into one that only uses public randomness while preserving the information revealed to each player? We prove that the answer is yes, at least for protocols that use a bounded number of rounds. As an application, we prove new direct sum theorems through the compression of interactive communication in the bounded-round setting. Furthermore, we show that if a Reverse Newman's Theorem can be proven in full generality, then full compression of interactive communication and fully-general direct-sum theorems will result.
Additional Metadata
Keywords communication complexity, interactive communication compression, interactive information complexity
THEME Information (theme 2)
Publisher IEEE Conference Publishing Services
Persistent URL dx.doi.org/10.1109/CCC.2013.12
Conference IEEE Conference on Computational Complexity
Citation
Brody, J, Buhrman, H.M, Koucky, M, Loff Barreto, B. S, Speelman, F, & Vereshchagin, N.K. (2013). Towards a Reverse Newman's Theorem in Interactive Information Complexity. In Computational Complexity (CCC), 2013 IEEE Conference on (pp. 24–33). IEEE Conference Publishing Services. doi:10.1109/CCC.2013.12