  A conjugate code pair is defined as a pair of linear codes either of which
contains the dual of the other. A conjugate code pair represents the essential
structure of the corresponding Calderbank-Shor-Steane (CSS) quantum
error-correcting code. It is known that conjugate code pairs are applicable to
quantum cryptography. In this work, a polynomial construction of conjugate code
pairs is presented. The constructed pairs achieve the highest known achievable
rate on additive channels, and are decodable with algorithms of polynomial
complexity.
