SIST-TP ISO/TR 17068:2013

TECHNICAL ISO/TR
REPORT 17068
First edition
2012-11-01
Information and documentation -
Trusted third party repository for
digital records
Information et documentation — Référentiel tiers de confiance pour
les enregistrements électroniques
Reference number
ISO/TR 17068:2012(E)
©
ISO 2012

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ISO/TR 17068:2012(E)

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© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any
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Published in Switzerland
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ISO/TR 17068:2012(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Terms and definitions . 1
3 Overview of a TTPR . 3
3.1 Necessity for a TTPR . 3
3.2 Requirements for trustworthiness . 4
3.3 TTPR components . 5
3.4 Characteristics of a TTPR . 6
4 TTPR services . 6
4.1 Service procedure . 6
4.2 TTPR service contracts . 6
4.3 TTPR services. 9
5 System requirements .18
5.1 General .18
5.2 Digital record repository system .18
5.3 Transmitter-receiver system .18
5.4 Network system .19
5.5 Time-stamping system .19
5.6 Trail management system .19
5.7 Security system of network system .20
5.8 Access control equipment .20
5.9 Disaster protection facility .20
5.10 System for certificate issuance and validation of digital record .20
5.11 Backup system .22
5.12 Remote repository system .22
6 Management requirements .22
6.1 General .22
6.2 Client management .22
6.3 Administrator’s role and authority management .23
6.4 Network and security management .23
6.5 Digital record management .24
6.6 Management of transmitted and received messages .26
6.7 Audit record management .27
6.8 Data backup and recovery management .28
6.9 Security management .29
6.10 Migration and receipt management .29
6.11 Client system management .30
Bibliography .32
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ISO/TR 17068:2012(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from
that which is normally published as an International Standard (“state of the art”, for example), it may
decide by a simple majority vote of its participating members to publish a Technical Report. A Technical
Report is entirely informative in nature and does not have to be reviewed until the data it provides are
considered to be no longer valid or useful.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TR 17068 was prepared by Technical Committee ISO/TC 46, Information and documentation,
Subcommittee SC 11, Archives/records management.
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ISO/TR 17068:2012(E)

Introduction
As digital records are the inevitable by-products of various business activities in electronic and/or
digital systems, there is an increasing need to secure the legal admissibility of digital records during
their period of retention. It is internationally agreed that “digital records shall not be denied validity or
1)
enforceability of legal recognition by reason of their format alone” . Despite this, it may be very difficult
for an organization to assert that its digital records are authentic and able to act as effective evidence
of business action over a long period. In many cases legal admissibility of digital records managed by
organizations’ records systems may not be ensured. As a result, there is a growing need for certification
services for digital records by neutral third parties.
In order to protect digital records from business disputes during the period they are required for
sustaining legal obligation and ongoing retention, it is essential to ensure that the authenticity, reliability
and integrity of digital records endures.
Digital signatures are a well-known means of maintaining the integrity of digital records. However, as a
digital signature can only ensure integrity within its validity time (generally one to two years or less),
most digitally signed records cannot ensure their integrity for longer than this validity time. As a result,
it may be very difficult for an individual record system to prove the integrity of their digital records for
the period of retention obligation, where this is longer than the validity period of the digital signature.
A possible solution can be provided by a Trusted Third Party Repository (TTPR) service.
A TTPR is defined as a set of services, systems and personnel that ensure that digital records, entrusted
to it by a client, remain and can be asserted to be reliable and authentic, with the aim of providing
reliable access to managed digital records to its clients for the period of obligation for retention. A TTPR
for digital records should provide trustworthy services for clients, which can be examined by interested
parties (i.e. inspector, auditor, evaluator). These TTPR services are helpful to identify the evidence
admissibility of clients’ digital records as a source of evidence.
This Technical Report describes the specific requirements for the trustworthy services provided by a
TTPR. Its main purpose is to ensure that digital records can retain the relevant evidence and information
in an ensured and trusted manner during the required period of retention.
1) UNCITRAL 200t, United Nations Convention on the Use of Electronic Communication in International Contracts.
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TECHNICAL REPORT ISO/TR 17068:2012(E)
Information and documentation - Trusted third party
repository for digital records
1 Scope
This Technical Report details the authorized custody services of a Trusted Third Party Repository
(TTPR) in order to ensure provable integrity and authenticity of the clients’ digital records and serve as
a source of reliable evidence.
It describes the services and processes to be provided by a TTPR for the clients’ digital records during
the retention period, to ensure trust. It also details the criteria of “trustworthiness” and the particular
requirements of TTPR services, hardware and software systems, and management.
This Technical Report has the limitation that the authorized custody of the stored records is between
only the third party and the client.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
client
individual or organization that contracts with the TTPR and obtains permission to use the TTPR services
2.2
client system
hardware and software used by a client to use the service provided by the TTPR
2.3
digital record
information in any format created, received and maintained by digital means, used as evidence and
information by an organization or person, in pursuance of legal obligations or in the transaction of business
NOTE Adapted from ISO 15489-1:2001.
2.4
digital signature
data appended to, or a cryptographic transformation of, a data unit that allows a recipient of the data unit
to prove the source and integrity of the unit and protect against forgery by, for example, the recipient
NOTE Adapted from ISO 7498-2:1989.
2.5
information package
content information and associated preservation description information which is needed to aid in the
identification and preservation of the authentic and reliable digital records
NOTE 1 The information package has associated packaging information used to delimit and identify the
content information and preservation description information.
NOTE 2 Adapted from ISO 14721:2012.
2.6
process
series of actions or events taking place in a defined manner leading to the provision of TTPR services
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2.7
public key certificate
digitally-signed statement that binds the value of a public key to the identity of the person, device or
service that holds the corresponding private key
NOTE Certificates are issued and signed by a certification authority (CA). The entity that receives a certificate
from a CA is the subject of that certificate.
2.8
service level agreement
SLA
written agreement between a service provider and a client that documents services and agreed service levels
NOTE Adapted from ISO/IEC 20000-1:2011.
2.9
system
hardware and software of the TTPR
2.10
trusted archival information package
TAIP
information package, consisting of the content information, creator’s digital signature and a TTPR or
third party’s timestamp, and the associated preservation description information, which is preserved
in a TTPR after verification
2.11
trusted dissemination information package
TDIP
information package, derived from one or more TAIPs, received by a client in response to a request to a TTPR
2.12
trusted submission information package
TSIP
information package that is delivered by a client to a TTPR with creator’s and sender’s digital signature
and a TTPR or third party’s timestamp, delivering the time and information of the sender
NOTE 1 Herein, the digital signature is prepared using the public key certificate and the time stamp is created
in accordance with the time stamping module provided by a TTPR.
NOTE 2 Adapted from ISO/TS 15000-2:2004.
2.13
trusted third party repository
TTPR
set of services, systems and personnel that ensure that the digital records entrusted to it by a client
remain and can be asserted to be reliable and authentic
NOTE This has the goal of providing reliable access to managed digital records to its clients in the period of
obligation for retention.
2.14
TTPR certificate
digital document issued to authenticate the digital record in the TTPR
2.15
TTPR service
intangible product that is the result of at least one activity performed at the interface between a
TTPR and a client
NOTE Adapted from ISO 9000:2005.
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2.16
third party
person or body that is recognized as being independent of the parties involved, as concerns the
issue in question
2.17
trustworthiness
quality (of a TTPR) of being dependable and reliable
NOTE A trustworthy TTPR can be trusted to deliver its services in an authentic manner by following
documented policies and processes and ensuring the accuracy, reliability and authenticity of the records in the
repository over time.
3 Overview of a TTPR
3.1 Necessity for a TTPR
With the development and advancement of information and communication technology (ICT) over the
last two decades, the use of digital records has increased greatly. Accordingly, the number of electronic
transactions carried out by individuals and organizations in their daily activities has increased. For
example, in international transactions, many documents and records in digital formats are exchanged
in order to initiate, process and complete transactions between importers and exporters. Banks are also
involved in electronic records exchanges to confirm credit or payment. In the health industry, treatment
records are exchanged between clinics or patients and insurance companies; order of treatment records
are exchanged between general clinics and specialized clinics. These kinds of individual or organizational
transactions are very common within one sector or across several industries. During these transactions,
digital records can be easily copied, modified and distributed by an unauthorized person. This aspect of
documents and records retained in digital formats may create the risk of alteration or forgery, and has
raised awareness of the need for the secure management and transaction of digital records.
To help prevent possible risks, some countries have enacted laws and regulations requiring provable
authenticity, reliability, integrity and accessibility as a precondition for legal effect and enforceability
of digital records. These regulations explain the requirements for adopting secured digital records
and for judging their evidential admissibility. However, these requirements only typically describe the
mandatory characteristics that retained digital records need to have, regardless of an organization’s
records management capability. While many organizations have implemented a records system for
themselves, implementation of electronic records exchange across organizations often faces a number
of challenges. Individuals are also limited in their ability to comply with legal requirements for the
admissibility of their digital records. This limitation might cause social problems, delay operational
processes, reduce efficiency and prevent electronic exchange.
Therefore, as the exchange of secure records becomes more significant for individual and/or
organizational collaboration, the social demand for a trustworthy electronic transaction environment
has emerged as one of the major issues in digital environments today. Protecting information in digital
records is beginning to be regarded as an indispensable precondition for operational efficiency and
economic benefit in organizations across all sectors and industries.
One way of resolving this situation is to build and use a TTPR. A third party is an independent
individual or organization that is separate from the direct interests of mutual parties, and that acts as
an intermediary when two parties are exchanging digital information in a secure manner. Society and
governments should be in a position to trust the third party. To prevent any complications that may
arise during electronic transactions, a TTPR operates systems and facilities and follows well-defined
procedures according to the principles and guidelines for managing digital records in a secure manner.
During these processes, the TTPR ensures the authenticity, reliability, integrity and usability of digital
records, for the period of the contracted service. In addition, the TTPR provides an official source of
digital records that are admissible as evidence from a third party in the event of a dispute between
parties regarding their records.
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TTPRs can play a significant role and provide several benefits to parties involved. A TTPR could
provide document digitization services for converting paper documents into digital records with legal
admissibility. It could also provide services for managing digital records. A TTPR is endowed with
authorized custody over the stored records. A TTPR also provides certification services by authenticating
digital documents and issuing certifications on documents processed and retained by the TTPR.
Furthermore, a TTPR works as an intermediary to provide a secure exchange of digital records between
creators, senders and receivers in many forms of electronic transactions (e.g. one-to-one party, one-to-
many parties, many-to-many parties in business transactions and operational workflows). As such, a
TTPR can provide a public service for secure electronic information exchange between individuals or
organizations.
As a result, a TTPR can have a role in the management of digital records produced or received in both
the public and the private sector. The TTPR helps reduce the cost of constructing and operating internal
repositories by enabling the outsourcing aspects of electronic records management. Recently, with
the increasing popularity of cloud computing service environments, the shift from traditional records
management to service-oriented approaches is appropriate. Therefore, TTPR services can be helpful for
effective and efficient management of digital records.
3.2 Requirements for trustworthiness
The trustworthiness requirements of the TTPR should meet the high level requirements in terms of
authenticity, reliability and integrity described in ISO 15489 (all parts) and should follow the legal
requirements for electronic communications formulated by UNCITRAL. Moreover, these requirements
need to extend to information packages driven from the reference model for information archival
suggested in ISO 14721 for the purpose of reliable custody.
A TTPR should follow the trustworthiness requirements broken down into the attributes of authenticity,
reliability and integrity described below:
— The authenticity of the client’s digital records is accounted for in a business context, for example,
the creators’ place of business at time of creation of the record should be retained. The TTPR should
be able to check this.
— The TTPR should agree with the client regarding the client’s role and responsibility for
authenticity during the service contract period. When the TTPR checks the state of authenticity
of the clients’ records, the client should be able to account for this. If a client can’t account for the
authenticity of its digital records, the TTPR should not classify those digital records as authentic.
— The authenticity of digital records created by the client is maintained using the timestamp and
digital signature applied at the time of ‘freezing’ the record. To ensure this, the clients’ digital
records system should attach the timestamp to created records, sourced from the time stamping
module provided by the TTPR. Also it should attach the clients’ digital signature to the digital
records. Using this digital signature, digital records that have been falsified can be recognized
immediately, and consequentially, their authenticity and integrity can be challenged.
— The reliability of digital records can be confirmed by verifying the custody of digital records.
However, the TTPR should specify only where the custody is between the TTPR and its clients.
— A client should transfer digital records to the TTPR as a package in the form of a Trusted
Submission Information Package (TSIP).
— The TTPR should confirm the reliable custody of clients’ digital records by validating received
clients’ TSIP regarding any change in the digital records and/or any transmission errors.
— The integrity of digital records should be retained after creation for the period of retention. After
confirming the authenticity and reliability requirements from transmitted digital records, the
TTPR should maintain the integrity for the period of retention by registering these records as a
TAIP package (i.e. the information package of the TTPR’s signed registration metadata, the attached
clients’ digital records and evidential history).
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The TTPR should retain and manage the registration metadata, including the time of registration,
retention period, client information, the history of digital records, etc. In order to be able to confirm
trustworthiness of the stored digital records, the TTPR should be able to document key processes in the
management of digital records, such as acquisition, retention, distribution, delivery and migration and
disposition, and provide the document to a client as proof when requested.
3.3 TTPR components
A TTPR comprises services, systems and personnel as shown in Figure 1.
Services are provided to a client by the TTPR after the client has been authorized to use the TTPR
service through a contract. The TTPR should provide all the services specified in the contract to the
client, to the agreed quality level. The client should also fulfil all the obligations in the contract. For
example, the client should include the metadata required for validation of the authenticity of digital
records into information packages. The TTPR should be able to verify the authenticity of the transmitted
digital records. Besides the service provider and the client, there are other parties indirectly related
to the TTPR, for example, the inspector, auditor, evaluator. They are referred to as interested parties.
The inspector is an individual/organization that reviews technical issues in detail to determine
whether the digital records stored in a TTPR have legal evidential admissibility. The auditor is an
individual/organization that audits and monitors whether a TTPR is managed according to the defined
procedures and guidelines. The evaluator is an individual/organization that mainly judges whether a
software/hardware system satisfies the necessary functional requirements. The evaluator checks and
verifies the TTPR based on objective and formally established criteria, to provide the basis by which
TTPR can secure the confidence of its clients.
The software/hardware system fulfils its role as a tool, allowing the TTPR to maintain trustworthiness
and provide different services required by clients. The transmission system, which allows the
client’s created digital record to be transmitted reliably with integrity, the verification system which
automatically validates the metadata required for authenticity check during the acquisition stage, and
the repository system for the retention and management of the digital record, are included in such
software/hardware system. Also, the client’s system is necessary for the TTPR to maintain a safe and
reliable transmission channel and use a standardized transmission package.
The TTPR’s personnel have two main tasks: management and marketing. The management task operates
software/hardware to provide the TTPR services and preserves service quality. The marketing task
performs public relations and collects the clients’ requirements.
Figure 1 — TTPR Overview
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3.4 Characteristics of a TTPR
For a TTPR to be a reliable agent of digital record management for clients, the TTPR should be capable
of providing consistent and stable service, have specialized competence to guarantee the evidential
admissibility of the digital records, and maintain neutrality toward all partie
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