77a8603f_ervation__Library_of_Congress___Definition
[Term] Fixity check [Definition] 
A mechanism to verify that a digital object has not been altered in an undocumented manner. Checksums, message digests and digital signatures are examples of tools to run fixity checks. Fixity information, the information created by these fixity checks, provides evidence for the integrity and authenticity of the digital objects and are essential to enabling trust. See also "Checksum" and "Digital Signature."
NDSA Levels of Preservation Glossary - National Digital Stewardship Alliance - Digital Preservation (Library of Congress)
Definition