A permutation cipher scheme using polynomials over a field is presente
d. A permutation as well as substitution plays a major role in almost
all conventional cryptosystems. But the security of the permutation de
pends on how symbols are permuted. This paper proposes the use of poly
nomials for the permutation and show that the scheme satisfies the fol
lowing security criteria. (1) There are enough encryption keys to defe
nd exhaustive attacks. (2) The permutation moves almost all samples in
to places which are different from the original places. (3) Most sampl
es are shifted differently by different permutations. The permutation
cipher scheme could be regarded as a scheme based on Reed-Solomon code
s. The information symbols of the codes compose a key of the permutati
on cipher scheme.