Multi-Bit Error Vulnerabilities in the Controller Area Network Protocol
Eushiuan Tran, Philip John Koopman · 1999
Embedded networks will increasingly be used in safety-critical applications such as drive-by-wire automobiles. Because of potentially high network noise in such systems, reliably detecting bit errors could become vital to preventing the dissemination of corrupted data. Unfortunately, an interaction between bit stuffing and use of a cyclic redundancy code (CRC) can create a vulnerability to undetected multi-bit errors. Simulations of the widely used Controller Area Network (CAN) protocol indicate that this problem can cause a double-bit error to result in a 1.3 x 10 -7 probability of undetected corruption. This number, although small, becomes an issue when magnified by a fleet size of hundreds of millions of vehicles. This vulnerability and related CAN specification problems can be fixed, albeit at a cost. A generalized lesson is that transmission encoding can undermine the effectiveness of error detection codes to the point that a system might not provide a required level of robustne...