In this, the 15th year of the 21st century, the need to translate plain text into code and to transmit securely, and the plethora of uses to which encryption is applied, needs no amplification. Recent methods have produced so-called cyclic codes, which have the property that if (a_1, a_2, a_3, ..., a_n) is a code word, then so is the cyclic shift (a_n, a_1, a_2, ..., a_{n-1}). The realization that such a code is an ideal in the group algebra of a...