Security of electronic records: designated officers must ensure access controls, integrity, backups and retrievability for company records. Rule 28 designates a senior officer as responsible for security of electronic records and requires measures to prevent unauthorized access, alteration or loss; validation and securing of systems to ensure accuracy and detection of altered records; storage in non rewritable, non erasable formats; authenticated dated backups kept securely; restricted access to authorized personnel; indexing for retrieval; and steps to preserve integrity, confidentiality and authenticity of records so signed electronic records cannot be repudiated.