\input zb-basic \input zb-ioport \iteman{io-port 02113949} \itemau{Nishio, Hidenosuke; Saito, Takashi} \itemti{Information dynamics of cellular automata. I: An algebraic study.} \itemso{Fundam. Inform. 58, No. 3-4, 399-420 (2003).} \itemab Summary: Information dynamics of Cellular Automata (CA) is studied using polynomials over finite fields. The information about the uncertainty of cell states is expressed by an indeterminate $X$ called information variable and its dynamics is investigated by extending CA to CA[$X$] whose cell states are polynomials in $X$. For the global configuration of extended CA[$X$], new notions of completeness and degeneracy are defined and their dynamical properties are investigated. A theorem is proved that completeness equals non-degeneracy. With respect to the reversibility, we prove that a CA is reversible, if and only if its extension CA[$X$] preserves the set of complete configurations. Information dynamics of finite CAs and linear CAs are treated in separate sections. Decision problems are also referred to. \itemrv{~} \itemcc{} \itemut{polynomials over finite fields; dynamical system} \itemli{} \end