An organization uses SHA-256 for data integrity verification but still experiences unauthorized data modification.

CEH explains that hash functions alone, such as SHA-256, only provide integrity checks and do not verify authenticity or non-repudiation. Attackers can modify data and recompute the hash.

Digital signatures combine hashing with asymmetric cryptography, ensuring:

Integrity

Authentication

Non-repudiation

Option D is correct.

Options A and B provide confidentiality, not integrity assurance.

Option C secures communication channels, not standalone data integrity.

CEH explicitly recommends digital signatures for protecting data integrity against tampering.