Archival data identification

Methods and systems are provided herein that facilitate cost-effective and reliable data identification in an archival data storage system. In an embodiment, a data object stored in an archival data storage system is identified by a data object identifier which encodes storage location information that may be used to locate a data object stored in an archival data storage system that reduces the cost to store a global index. The data object identifier may also encode policy information such as access control information usable for validating subsequent access to the data object, payload validation information such as size and digest usable for verifying the integrity of the payload data, metadata validation information such as error-detection codes usable for validating integrity of the data object identifier and other information.