A Security Engineer Is Assisting a Developer with Input Validation

Multiple Choice

A security engineer is assisting a developer with input validation, and they are studying the following code block: The security engineer wants to ensure strong input validation is in place for customer-provided account identifiers. These identifiers are ten-digit numbers. The developer wants to ensure input validation is fast because a large number of people use the system. Which of the following would be the BEST advice for the security engineer to give to the developer?

A) Replace code with Java-based type checks
B) Parse input into an array
C) Use regular expressions
D) Canonicalize input into string objects before validation