Question 16.89
59. The Canadian province of Quebec assigns a check digit to an 11-digit driver’s license number so that is divisible by 10. Criticize this method. Describe all single-digit errors that are undetected by this scheme.
59.
Many single-digit errors go undetected. Substitution of for where is 5 or −5 in positions 1, 5, 7, 9, and 11 is undetected; all errors in position 3 are undetected; substitution of for where is even in position 8 is undetected.