Fault tolerant bit parallel finite field multipliers using LDPC codes

Motivated by the problems associated with soft errors in digital circuits and fault related attacks in cryptographic hardware, we presented a systematic method for designing single error correcting multiplier circuits for finite fields or Galois fields over GF(2(m)) in [7]. We used multiple parity predictions to correct single errors based on the Hamming principles. The problem with Hamming based error correction is the delay overhead. To mitigate the delay overhead, in this paper we present single error correction using Low Density Parity Check Codes (LDPC). The expressions for the parity prediction are derived from the input operands, and are based on the primitive polynomials of the fields. Our technique, when compared with existing techniques, gives better performance. We show that our Single Error Correction (SEC) multipliers over GF(21) require slightly over 100 percent extra hardware, whereas with the traditional SEC techniques this figure is more than 200 percent.