CIST M: Content Immutable Storage for Trustworthy Electronic Record Keeping

As records are increasingly generated in large volumes and in electronic form, which allows easy destruction and clandestine modification, it is imperative that they be properly managed to preserve their trustworthiness, i.e., their ability to provide irrefutable proof and accurate details of events that have occurred. The need for proper record keeping is further underscored by the recent corporate misconduct and ensuing attempts to destroy incriminating records. We critically examine the purpose and process of record keeping to establish the storage system requirements for ensuring that records are trustworthy. We refer to a storage system that meets these requirements as content immutable storage (CIS). CIS offers overwrite protection that is secure even against inside attacks, supports index mechanisms efficiently, allows records to be properly disposed of after they have expired, and is low in cost yet reliable. We also discuss design issues in satisfying the requirements and describe a prototype implementation of CIS. Performance results obtained on the prototype suggest that CIS performs similarly to regular storage for the record keep-