This policy is informed by the concepts described in the performance model. The Archives developed the performance model as a way of understanding the nature of digital records. The model states that data (the source) requires the application of a set of technologies (the process) to render its information content (the performance).

Fig. 1 Experience of a digital record

According to the model, the preservation of a digital record should focus on maintaining the performance of the record over time, rather than attempting to preserve the specific combination of source and process that supported the record when it was created. Provided that the performance can be replicated over time, the particular source and process used to render it can be changed.

The performance model is a powerful framework for describing digital preservation strategies. For example, under this model normalisation strategies change the source so that it can always be rendered by current processes, while emulation strategies maintain the source, but change the processes required to render it. The performance is defined in terms of the significant properties of the record, which must always be preserved in the performance. The persistence of these properties is fundamental to the authenticity of the record.

The Archives will align its policies with OAIS wherever practicable. OAIS is a highly influential ISO standard that provides a common framework, including terminology and concepts, for describing a digital archive.

OAIS does not just focus on the technical architecture and processes for a digital archive, but gives equal importance to people and policies as constituent parts of a digital archive.

Fig. 2 OAIS Model diagram

Metadata is essential for the effective management, preservation and use and reuse of records. The types of metadata used to support the management of authentic digital records include:

• Descriptive metadata, which describes the intellectual record and its context
• Technical metadata, such as the file format of the digital record, resolution, the size of the digital record, the software in which the record was created and managed
• Access and rights metadata, defining who is allowed to view the record under what conditions, and what they can do with it (reuse)
• Preservation metadata, which keeps track of actions taken to preserve or sustain the record for later access and use.

Different metadata standards, and different schemas, are required for these purposes. The Archives' standard for descriptive metadata on records in Archives' custody is the Commonwealth Record Series (CRS) system. The industry standard for preservation metadata is PREMIS. Agencies may have developed bespoke technical metadata schemas to manage particular digital resources. These metadata schemas will be recorded in a metadata registry and metadata repository with persistent links to the digital objects.

Subject to an assessment of the reliability of the source, the Archives will always generate and process metadata systematically and through highly automated processes such as an application programming interface (API). Wherever possible, the Archives sources recordkeeping and technical metadata from the creating agency which is reused for archival management and control. This is supplemented by metadata which is systematically extracted from the digital objects themselves. Manual metadata creation will normally be feasible only at a very high-level of description, for example to describe the Series or the Agency. The Archives acknowledges that data is imperfect and we cannot always be confident that it is accurate. We will mitigate this risk by ensuring that agencies are compliant with our standards and advice, and by assessing, securing and validating metadata at the point of transfer.

The metadata model used by the Archives must be capable of describing multiple versions of a digital record, and creating a complete audit trail of the preservation actions that have generated those versions. This model must also accurately document the relationships between digital records, and between records and records’ creators. This relationship does not always reflect the traditional archival hierarchy of Organisation, Agency, Function, Series, Item. Digital records can be threaded discussions using a web-based application, a tweet with embedded video, websites, structured datasets and computer code. The metadata model used by the Archives must allow for more fluid and interlinked relationships between entities and objects. The Archives will draw on initiatives like the International Council on Archives’ Records in Contexts (RiC) to develop new models of contextual description that extend the flexibility of the CRS system.

The Archives endorses the use of open, standards-based formats and accepted, well-documented industry standards, and will publish its born-digital file formats standards .

The Archives prescribes long-term preservation file formats for categories of digital records. The Archives will investigate and conduct risk assessments of file formats to determine which formats are low risk for the long-term preservation of information. This work will draw on national and international best practice.

5.4.1 Criteria for long term preservation formats

In determining long-term preservation formats, the Archives will take account of format characteristics:

• Widely adopted: The format is widely used and supported around the world.
• Unrestricted: The format is free from patents and legal encumbrance. It preferably uses open-source principles.
• Well documented: The format is identifiable and the specification is publicly available. The specification is detailed enough that people with the right skills can create software to display it correctly.
• Stable: The file format is stable and new versions are only released rarely. The format is backwards- and forwards-compatible or has a clear migration path.
• Platform independent: The format is supported by a wide range of software or is platform-independent.
• Uncompressed: The format is uncompressed or uses lossless compression.
• Supported: Technical support is readily available from vendors, the community or third parties.
• Metadata friendly: The file format supports metadata.

These criteria are based on the work on long-term preservation formats undertaken by the Australasian Digital Records Initiative (ADRI).

5.4.2 At-risk formats

'At-risk' formats are formats that the Archives has determined are a high risk of being inaccessible within a short period of time. Records in these formats are normalised into 'preferred' preservation formats. The original bitstream is also retained. In determining 'at-risk' formats, the Archives will take account of one or more of the following characteristics:

• the format is poorly documented
• patent or licence restrictions apply to the format
• there is limited choice of software implementing the format
• the format is not supported
• the international digital preservation community has determined that the format is at-risk.

The Archives publicly documents our internal standards for the creation of digital surrogates, including preservation master files, and provides guidance to agencies on creation of digital surrogates.

The record must be trusted as an accurate representation of the original record. The Archives will ensure authenticity through the operation of transparent and fully documented preservation strategies, and by capturing and providing the metadata required to describe the content, context and provenance of the record.

The record must be complete and protected against unauthorised or accidental alteration. The Archives ensures the integrity of the record by always keeping the original record (bitstream preservation), fixity checking of digital objects, and capturing a full audit trail of all preservation actions performed on the record.

The record must be capable of being accessed by users, across time and changing technical environments. This requires that the record be locatable and retrievable, that it can be rendered in a current technical environment, and that it can be understood and interpreted by users. The Archives ensures the usability through:

• digital preservation strategies to ensure that content remains accessible over time, for example migration or emulation strategies.
• capture and provision of metadata sufficient to allow the record to be located, retrieved and understood
• making digital records accessible without restriction, unless there is a justifiable reason to restrict or close access, for example an exemption under Section 33 of the Archives Act.

The Archives will continue to develop its ability to provide access to digital records in new and innovative ways to meet the evolving needs and expectations of our users.

The Archives takes a risk-based approach to digital preservation and employs several strategies to enable effective preservation of the digital collection.

The preservation of digital records is a complex task: the physical media, encoding format, preservation software and method must be carefully and persistently managed in order to preserve the records. The Archives will implement different preservation strategies over time, for different types of digital records.

These strategies will be selected according to the requirements of particular record types, evolving international best practice, and the resources required to carry out the preservation strategy. Irrespective of the strategies employed at a given time, the Archives will always retain the original digital record (bitstream preservation), and may retain all intermediate versions created as a result of preservation actions.

Both digital preservation and digitisation involve the copying of content. Therefore, copying for preservation is subject to copyright legislation. The Archives will comply with intellectual property rights and with other legal and moral rights related to copying, storage, modification of content, and the use of digital records.

The Archives will ensure the complete and full capture of digital records at the time of transfer. Inadequate or incomplete capture results in inauthentic and unreliable records. The Archives will ensure complete capture through:

Transfer validation: Archives staff will quality check transfers to ensure the transfer is properly authorised and that the digital records have been sentenced Retain as National Archives (RNA) against a current Records Authority. Archives staff will check the quality, comprehensiveness and accessibility of digital records and enforce minimum standards at the time of transfer. The Archives will not accept for transfer digital records that are password protected, encrypted, or which have viruses or other malware.

Metadata validation: this ensures that the metadata we receive is technically correct and prevents changes to metadata we receive in the transfer process, for example the last modified date.

Fixity checking: this is used to prevent any alterations to the digital records during the transfer process. Checksums are generated prior to transfer and are checked when the transfer is received by the Archives.

Transfer complete datasets and metadata: Archives staff will actively seek to transfer complete datasets and metadata. The future opportunities to analyse complete sets of data (as opposed to partial or sample datasets) can fundamentally change the value of that information.

The Archives will achieve its objectives through digital preservation infrastructure that ensures data integrity, format sustainability, and information security. The Archives will do this through:

Storage selection: carefully select storage technologies to maximise the periods between refreshment cycles, and simplify the refreshment process itself, in addition to providing the most secure storage environment possible. Detailed criteria and methods for selecting appropriate storage solutions, including cloud services, will be developed as part of the storage procurement process.

Redundancy and back-up: maintain redundant copies of digital records through appropriate replication and backup processes. The viability and integrity of backup copies, including the ability to restore from backups, will be periodically tested.

Data integrity: malware scanning and checking for file fixity. Files with fixity issues will be repaired and/or replaced.

Information security: identify and enforce who has access to digital archive systems and services, and create and maintain complete record logs of processing actions. Provide a secure and stable digital platform to protect against cyber threats.

The Archives undertakes two fundamental preservation activities:

Bit preservation: this approach involves maintaining the digital record in its original format. Bit preservation is ensured by having a number of independent copies of the digital record, regularly checking the integrity of the copies, and restoring the digital record where error is detected. The purpose of bit preservation is to ensure the continuing integrity of the digital record.

Normalisation: this approach involves converting a digital record from an at-risk data format to a preservation format in order to ensure its continued accessibility with current technology.

The Archives conducts format assessments to determine the risk level of particular formats. The risk assessment is used to determine whether a digital record is normalised or maintained in its original format.

Preservation processes that result in any physical or logical change to a digital object will be logged and recorded in the associated metadata, to provide an audit trail. All changes to metadata will themselves be audited.

The relationship between any digital object and its metadata be maintained persistently. A persistent, unique identifier will be assigned to every digital object at the point of ingest, and the recording of this identifier within the associated metadata to provide a persistent link.

Digital records and digitised records will be delivered to users in ways that do not limit the use and re-use of the records' content, for example a download of a digital record in its original format, or a download of an unsecured pdf access copy of a digitised record.

Archives Act 1983

Privacy Act 1988

Freedom of Information Act 1982

Evidence Act 1995

Electronic Transactions Act 1999

ISO 14721:2012 Space data and information transfer systems – Open archival information system (OAIS) – Reference model (PDF, 1.86MB)

ISO 20652:2006 Space data and information transfer systems – Producer-archive interface

AS ISO 18492-2006 Long-term preservation of electronic-based information

SA/SNZ TS ISO/IEC 20000

ISO/IEC 27000:2018 Information technology - Security techniques - Information security management systems - Overview and vocabulary

AS/NZS ISO/IEC 27001:2023 Information security, cybersecurity and privacy protection - Information security management systems - Requirements

AS/NZS ISO/IEC 27002:2022 Information security, cybersecurity and privacy protection - Information security controls

AS/NZS ISO/IEC 27005:2012 Information technology – Security techniques – Information security risk management

National Archives of Australia, Commonwealth Record Series (CRS) Manual (2004)

National Archives of Australia, Australian Government Recordkeeping Metadata Standard (AGRkMS) Version 2.2 (PDF, 1.9MB)

PREMIS Data Dictionary for Preservation Metadata, version 3.0

National Archives of Australia, Performance Model – An Approach to the Preservation of Digital Records

Records in Context (RiC) – Conceptual Model – International Council on Archives

ISAD(G) – International Council on Archives: General International Standard Archival Description, 2nd ed., (2000)

Australian Government Information Security Manual (ISM)

Protective Security Policy Framework