Integrity

The security goal that generates the requirement for protection against either intentional or accidental attempts to violate data integrity (the property that data has not been altered in an unauthorized manner) or system integrity (the quality that a system has when it performs its intended function in an unimpaired maner, free and unauthorized manipulation). NIST SP 800-27 Rev A

Guarding against improper information modification or destruction, and includes ensuring information non-repudiation and authenticity. NIST SP 800-160