Information has a number of reliability aspects. Reliability is constantly being threatened. Examples of threats are: a cable becomes loose, someone alters information by accident, data is used privately or is falsified. Which of these examples is a threat to integrity?

Integrity, in the context of information security, refers to maintaining the accuracy and completeness of data and processing methods. It ensures that information is not altered in an unauthorized or undetected manner. The accidental alteration of data is a direct breach of this principle because the data is no longer in its correct, trustworthy state. This event compromises the reliability and correctness of the information, which is the essence of what integrity aims to protect. The other options relate to different pillars of information security: availability and confidentiality.

A. a loose cable: This is a threat to availability, as it can disrupt access to information systems and data.
C. private use of data: This is a threat to confidentiality, as it implies unauthorized access or disclosure of information.
D. System restart: This is a threat to availability, as it causes a temporary interruption of access to the system and its data.

1. ISO/IEC 27000:2018, Information technology — Security techniques — Information security management systems — Overview and vocabulary.

Clause 3.28: Defines integrity as the "property of accuracy and completeness." Accidental alteration directly violates this.

Clause 3.3: Defines availability as the "property of being accessible and usable on demand by an authorized entity." A loose cable or system restart threatens this.

Clause 3.7: Defines confidentiality as the "property that information is not made available or disclosed to unauthorized individuals, entities, or processes." Private use of data is a threat to this.

2. University of Illinois, IT Policy - The CIA Triad. This university resource explains the core principles of information security. It states, "Integrity is the 'I' in the C-I-A triad. The integrity of information refers to protecting information from being modified by unauthorized parties." This directly supports that alteration (accidental or otherwise) is an integrity issue.

3. Pfleeger, C. P., & Pfleeger, S. L. (2003). Security in Computing. Prentice Hall. (A foundational academic textbook used in university curricula). Chapter 1, Section 1.2, "The Meaning of Computer Security," details the CIA triad. It describes integrity as ensuring data is not "improperly modified," distinguishing it from availability (accessible when needed) and confidentiality (preventing unauthorized disclosure).