Validation definition in Computer Security terms:
Confirmation (through the provision of strong, sound, objective evidence) that requirements for a specific intended use or application have been fulfilled (e.g., a trustworthy credential has been presented, or data or information has been formatted in accordance with a defined set of rules, or a specific process has demonstrated that an entity under consideration meets, in all respects, its defined attributes or requirements).
Source(s): CNSSI 4009-2015
The process of determining that an object or process is acceptable according to a pre-defined set of tests and the results of those tests.
Source(s): NIST SP 800-152
reference: CSRC Glossary