ISO 17090-1:2013

INTERNATIONAL ISO
STANDARD 17090-1
Second edition
2013-05-01
Health informatics — Public key
infrastructure —
Part 1:
Overview of digital certificate services
Informatique de santé — Infrastructure de clé publique —
Partie 1: Vue d’ensemble des services de certificat numérique
Reference number
©
ISO 2013
© ISO 2013
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ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Healthcare context terms . 1
3.2 Security services terms . 3
3.3 Public key infrastructure related terms . 6
4 Abbreviations. 9
5 Healthcare context . 9
5.1 Certificate holders and relying parties in healthcare . 9
5.2 Examples of actors .10
5.3 Applicability of digital certificates to healthcare .11
6 Requirements for security services in healthcare applications .12
6.1 Healthcare characteristics .12
6.2 Digital certificate technical requirements in healthcare.13
6.3 Healthcare-specific needs and the separation of authentication from
data encipherment.14
6.4 Health industry security management framework for digital certificates .14
6.5 Policy requirements for digital certificate issuance and use in healthcare .14
7 Public key cryptography .15
7.1 Symmetric vs. asymmetric cryptography .15
7.2 Digital certificates.15
7.3 Digital signatures .15
7.4 Protecting the private key .16
8 Deploying digital certificates .17
8.1 Necessary components .17
8.2 Establishing identity using qualified certificates .18
8.3 Establishing speciality and roles using identity certificates .18
8.4 Using attribute certificates for authorisation and access control .19
9 Interoperability requirements .20
9.1 Overview .20
9.2 Options for deploying healthcare digital certificates across jurisdictions .20
9.3 Option usage .22
Annex A (informative) Scenarios for the use of digital certificates in healthcare .23
Bibliography .38
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.
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 17090-1 was prepared by Technical Committee ISO/TC 215, Health informatics.
This second edition cancels and replaces the first edition (ISO 17090-1:2008), of which it constitutes a
minor revision.
ISO 17090 consists of the following parts, under the general title Health informatics — Public key
infrastructure:
— Part 1: Overview of digital certificate services
— Part 2: Certificate profile
— Part 3: Policy management of certification authority
Annex A of this part of ISO 17090 is for information only.
iv © ISO 2013 – All rights reserved

Introduction
The healthcare industry is faced with the challenge of reducing costs by moving from paper-based
processes to automated electronic processes. New models of healthcare delivery are emphasizing the
need for patient information to be shared among a growing number of specialist healthcare providers
and across traditional organisational boundaries.
Healthcare information concerning individual citizens is commonly interchanged by means of electronic
mail, remote database access, electronic data interchange, and other applications. The Internet provides
a highly cost-effective and accessible means of interchanging information, but it is also an insecure vehicle
that demands additional measures be taken to maintain the privacy and confidentiality of information.
Threats to the security of health information through unauthorised access (either inadvertent or
deliberate) are increasing. It is essential to have available to the healthcare system reliable information
security services that minimise the risk of unauthorised access.
How does the healthcare industry provide appropriate protection for the data conveyed across the
Internet in a practical, cost-effective way? Public key infrastructure (PKI) and digital certificate
technology seek to address this challenge.
The proper deployment of digital certificates requires a blend of technology, policy, and administrative
processes that enable the exchange of sensitive data in an unsecured environment by the use of “public
key cryptography” to protect information in transit and “certificates” to confirm the identity of a person
or entity. In healthcare environments, this technology uses authentication, encipherment, and digital
signatures to facilitate confidential access to, and movement of, individual health records to meet
both clinical and administrative needs. The services offered by the deployment of digital certificates
(including encipherment, information integrity, and digital signatures) are able to address many of
these security issues. This is especially the case if digital certificates are used in conjunction with an
accredited information security standard. Many individual organisations around the world have started
to use digital certificates for this purpose.
Interoperability of digital certificate technology and supporting policies, procedures, and practices
is of fundamental importance if information is to be exchanged between organisations and between
jurisdictions in support of healthcare applications (for example between a hospital and a community
physician working with the same patient).
Achieving interoperability between different digital certificate implementations requires the
establishment of a framework of trust, under which parties responsible for protecting an individual’s
information rights may rely on the policies and practices and, by extension, the validity of digital
certificates issued by other established authorities.
Many countries are deploying digital certificates to support secure communications within their national
boundaries. Inconsistencies will arise in policies and procedures between the certification authorities
(CAs) and the registration authorities (RAs) of different countries if standards development activity is
restricted to within national boundaries.
Digital certificate technology is still evolving in certain aspects that are not specific to healthcare.
Important standardisation efforts and, in some cases, supporting legislation are ongoing. On the other
hand, healthcare providers in many countries are already using or planning to use digital certificates.
This International Standard seeks to address the need for guidance of these rapid international
developments.
This International Standard describes the common technical, operational, and policy requirements that
need to be addressed to enable digital certificates to be used in protecting the exchange of healthcare
information within a single domain, between domains, and across jurisdictional boundaries. Its purpose
is to create a platform for global interoperability. It specifically supports digital certificate-enabled
communication across borders, but could also provide guidance for the national or regional deployment
of digital certificates in healthcare. The Internet is increasingly used as the vehicle of choice to support
the movement of healthcare data between healthcare organisations and is the only realistic choice for
cross-border communication in this sector.
This International Standard should be approached as a whole, with the three parts all making a
contribution to defining how digital certificates can be used to provide security services in the health
industry, including authentication, confidentiality, data integrity, and the technical capacity to support
the quality of digital signature.
ISO 17090-1 defines the basic concepts underlying the use of digital certificates in healthcare and
provides a scheme of interoperability requirements to establish digital certificate-enabled secure
communication of health information.
ISO 17090-2 provides healthcare specific profiles of digital certificates based on the International
Standard X.509 and the profile of this specified in IETF/RFC 3280 for different types of certificates.
ISO 17090-3 deals with management issues involved in implementing and using digital certificates in
healthcare. It defines a structure and minimum requirements for certificate policies (CPs) and a structure
for associated certification practice statements. ISO 17090-3 is based on the recommendations of the
informational IETF/RFC 3647, Internet X.509 Public Key Infrastructure Certificate Policy and Certification
Practices Framework, and identifies the principles needed in a healthcare security policy for cross border
communication. It also defines the minimum levels of security required, concentrating on the aspects
unique to healthcare.
Comments on the content of this International Standard, as well as comments, suggestions, and
information on the application of these standards may be forwarded to the ISO/TC 215 secretariat.
vi © ISO 2013 – All rights reserved

INTERNATIONAL STANDARD ISO 17090-1:2013(E)
Health informatics — Public key infrastructure —
Part 1:
Overview of digital certificate services
1 Scope
This part of ISO 17090 defines the basic concepts underlying the use of digital certificates in healthcare
and provides a scheme of interoperability requirements to establish a digital certificate-enabled secure
communication of health information. It also identifies the major stakeholders who are communicating
health-related information, as well as the main security services required for health communication
where digital certificates may be required.
This part of ISO 17090 gives a brief introduction to public key cryptography and the basic components
needed to deploy digital certificates in healthcare. It further introduces different types of digital
certificates — identity certificates and associated attribute certificates for relying parties, self-signed
certification authority (CA) certificates, and CA hierarchies and bridging structures.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 17090-2:2008, Health informatics — Public key infrastructure — Part 2: Certificate profile
ISO 17090-3:2008, Health informatics — Public key infrastructure — Part 3: Policy management of
certification authority
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Healthcare context terms
3.1.1
application
identifiable computer running software process that is the holder of a private encipherment key
Note 1 to entry: Application, in this context, can be any software process used in healthcare information systems,
including those without any direct role in treatment or diagnosis.
Note 2 to entry: In some jurisdictions, including software, processes can be regulated medical devices.
3.1.2
device
identifiable computer-controlled apparatus or instrument that is the holder of a private encipherment key
Note 1 to entry: This includes the class of regulated medical devices that meet the above definition.
Note 2 to entry: Device, in this context, is any device used in healthcare information systems, including those
without any direct role in treatment or diagnosis.
3.1.3
healthcare actor
regulated health professional, non-regulated health professional, sponsored healthcare provider,
supporting organisation employee, patient/consumer, healthcare organisation, device, or application
that acts in a health-related communication and requires a certificate for a digital certificate-enabled
security service
3.1.4
healthcare organisation
officially registered organisation that has a main activity related to healthcare services or health promotion
EXAMPLE Hospitals, Internet healthcare website providers, and healthcare research institutions.
Note 1 to entry: The organisation is recognised to be legally liable for its activities but need not be registered for
its specific role in health.
Note 2 to entry: An internal part of an organisation is called here an organisational unit, as in X.501.
3.1.5
non-regulated health professional
person employed by a healthcare organisation who is not a regulated health professional
EXAMPLE Medical receptionist who organises appointments or nurses aid who assists with patient care.
Note 1 to entry: The fact that the employee is not authorised by a body independent of the employer in his/her
professional capacity does, of course, not imply that the employee is not professional in conducting his/her services.
3.1.6
organisation employee
person employed by a healthcare organisation or a supporting organisation
EXAMPLE Medical records transcriptionists, healthcare insurance claims adjudicators, and pharmaceutical
order entry clerks.
3.1.7
patient
consumer
person who is the receiver of health-related services and who is an actor in a health information system
3.1.8
privacy
freedom from intrusion into the private life or affairs of an individual when that intrusion results from
undue or illegal gathering and use of data about that individual
[SOURCE: ISO/IEC 2382-8:1998]
3.1.9
regulated health professional
person who is authorised by a nationally recognised body to be qualified to perform certain health services
EXAMPLE Physicians, registered nurses, and pharmacists.
Note 1 to entry: The types of registering or accrediting bodies differ in different countries and for different
professions. Nationally recognised bodies include local or regional governmental agencies, independent
professional associations, and other formally and nationally recognised organisations. They may be exclusive or
non-exclusive in their territory.
Note 2 to entry: A nationally recognised body in this definition does not imply one nationally controlled system
of professional registration but, in order to facilitate international communication, it would be preferable for one
nationwide directory of recognised health professional registration bodies to exist.
2 © ISO 2013 – All rights reserved

3.1.10
sponsored healthcare provider
health services provider who is not a regulated professional in the jurisdiction of his/her practice, but
who is active in his/her healthcare community and sponsored by a regulated healthcare organisation
EXAMPLE A drug and alcohol education officer who is working with a particular ethnic group, or a healthcare
aid worker in a developing country.
3.1.11
supporting organisation
officially registered organisation which is providing services to a healthcare organisation, but which is
not providing healthcare services
EXAMPLE Healthcare financing bodies such as insurance institutions, suppliers of pharmaceuticals and
other goods.
3.2 Security services terms
3.2.1
access control
means of ensuring that the resources of a data processing system can be accessed only by authorised
entities in authorised ways
[SOURCE: ISO/IEC 2382-8:1998]
3.2.2
accountability
property that ensures that the actions of an entity may be traced uniquely to the entity
[SOURCE: ISO 7498-2:1989]
3.2.3
asymmetric cryptographic algorithm
algorithm for performing encipherment or the corresponding decipherment in which the keys used for
encipherment and decipherment differ
[SOURCE: ISO/IEC 10181-1:1996]
3.2.4
authentication
process of reliably identifying security subjects by securely associating an identifier and its authenticator
[SOURCE: ISO 7498-2:1989]
Note 1 to entry: See also data origin authentication and peer entity authentication.
3.2.5
authorisation
granting of rights, which includes the granting of access based on access rights
[SOURCE: ISO 7498-2:1989]
3.2.6
availability
property of being accessible and useable upon demand by an authorised entity
[SOURCE: ISO 7498-2:1989]
3.2.7
ciphertext
data produced through the use of encipherment, the semantic content of which is not available
Note 1 to entry: Adapted from ISO 7498-2:1989.
3.2.8
confidentiality
property that information is not made available or disclosed to unauthorised individuals, entities, or
processes
[SOURCE: ISO 7498-2:1989]
3.2.9
cryptography
discipline which embodies principles, means, and methods for the transformation of data in order to
hide its information content, prevent its undetected modification, and/or prevent its unauthorised use
[SOURCE: ISO 7498-2:1989]
3.2.10
cryptographic algorithm
cipher
method for the transformation of data in order to hide its information content, prevent its undetected
modification, and/or prevent its unauthorised use
[SOURCE: ISO 7498-2:1989]
3.2.11
data integrity
property that data have not been altered or destroyed in an unauthorised manner
[SOURCE: ISO 7498-2:1989]
3.2.12
data origin authentication
corroboration that the source of data received is as claimed
[SOURCE: ISO 7498-2:1989]
3.2.13
decipherment
decryption
process of obtaining, from a ciphertext, the original corresponding data
[SOURCE: ISO/IEC 2382-8:1998]
Note 1 to entry: A ciphertext may be enciphered a second time, in which case a single decipherment does not
produce the original plaintext.
3.2.14
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 data unit and protect against forgery, e.g. by the recipient
[SOURCE: ISO 7498-2:1989]
Note 1 to entry: See cryptography.
4 © ISO 2013 – All rights reserved

3.2.15
encipherment
encryption
cryptographic transformation of data to produce ciphertext
[SOURCE: ISO 7498-2:1989]
Note 1 to entry: See cryptography.
3.2.16
identification
performance of tests to enable a data processing system to recognise entities
[SOURCE: ISO/IEC 2382-8:1998]
3.2.17
identifier
piece of information used to claim an identity, before a potential corroboration by a corresponding
authenticator
[SOURCE: ENV 13608-1]
3.2.18
integrity
proof that the message content has not been altered, deliberately or accidentally, in any way during
transmission
Note 1 to entry: Adapted from ISO 7498-2:1989.
3.2.19
key
sequence of symbols that controls the operations of encipherment and decipherment
[SOURCE: ISO 7498-2:1989]
3.2.20
key management
generation, storage, distribution, deletion, archiving, and application of keys in accordance with a
security policy
[SOURCE: ISO 7498-2:1989]
3.2.21
non-repudiation
service providing proof of the integrity and origin of data (both in an unforgeable relationship), which
can be verified by any party
[19]
Note 1 to entry: Adapted from Reference.
3.2.22
private key
key that is used with an asymmetric cryptographic algorithm and whose possession is restricted
(usually to only one entity)
[SOURCE: ISO/IEC 10181-1:1996]
3.2.23
public key
key that is used with an asymmetric cryptographic algorithm and that can be made publicly available
[SOURCE: ISO/IEC 10181-1:1996]
3.2.24
role
set of behaviours that is associated with a task
3.2.25
security
combination of availability, confidentiality, integrity, and accountability
[SOURCE: ENV 13608-1]
3.2.26
security policy
plan or course of action adopted for providing computer security
[SOURCE: ISO/IEC 2382-8:1998]
3.2.27
security service
service, provided by a layer of communicating open systems, which ensures adequate security of the
systems or of data transfers
[SOURCE: ISO 7498-2:1989]
3.3 Public key infrastructure related terms
3.3.1
attribute authority
AA
authority which assigns privileges by issuing attribute certificates
[SOURCE: X.509]
3.3.2
attribute certificate
data structure, digitally signed by an attribute authority, that binds some attribute values with
identification about its holder
[SOURCE: X.509]
3.3.3
authority certificate
certificate issued to a certification authority or to an attribute authority
Note 1 to entry: Adapted from X.509.
3.3.4
certificate
public key certificate
3.3.5
certificate distribution
act of publishing certificates and transferring certificates to security subjects
3.3.6
certificate extension
extension fields (known as extensions) in X.509 certificates that provide methods for associating
additional attributes with users or public keys and for managing the certification hierarchy
Note 1 to entry: Certificate extensions may be either critical (i.e. a certificate-using system has to reject the
certificate if it encounters a critical extension it does not recognise) or non-critical (i.e. it may be ignored if the
extension is not recognised).
6 © ISO 2013 – All rights reserved

3.3.7
certificate generation
act of creating certificates
3.3.8
certificate management
procedures relating to certificates, i.e. certificate generation, certificate distribution, certificate
archiving and revocation
3.3.9
certificate profile
specification of the structure and permissible content of a certificate type
3.3.10
certificate revocation
act of removing any reliable link between a certificate and its related owner (or security subject owner)
because the certificate is not trusted any more, even though it is unexpired
3.3.11
certificate holder
entity that is named as the subject of a valid certificate
3.3.12
certificate verification
verifying that a certificate is authentic
3.3.13
certification
procedure by which a third party gives assurance that all or part of a data processing system conforms
to security requirements
[SOURCE: ISO/IEC 2382-8:1998]
3.3.14
certification authority
CA
certificate issuer
authority trusted by one or more relying parties to create and assign certificates and which may,
optionally, create the relying parties’ keys
Note 1 to entry: Adapted from ISO/IEC 9594-8:2008.
Note 2 to entry: Authority in the CA term does not imply any government authorisation but only denotes that
it is trusted.
Note 3 to entry: Certificate issuer may be a better term, but CA is very widely used.
3.3.15
certificate policy
CP
named set of rules that indicates the applicability of a certificate to a particular community and/or class
of application with common security requirements
[SOURCE: IETF/RFC 3647]
3.3.16
certification practices statement
CPS
statement of the practices which a certification authority employs in issuing certificates
[SOURCE: IETF/RFC 3647]
3.3.17
public key certificate
PKC
X.509 public key certificates (PKCs) which bind an identity and a public key
Note 1 to entry: The identity may be used to support identity-based access control decisions after the client proves
that it has access to the private key that corresponds to the public key contained in the PKC.
Note 2 to entry: Adapted from IETF/RFC 3280.
3.3.18
public key infrastructure
PKI
infrastructure used in the relation between a key holder and a relying party that allows a relying party
to use a certificate relating to the key holder for at least one application using a public key dependent
security service and that includes a certification authority, a certificate data structure, means for the
relying party to obtain current information on the revocation status of the certificate, a certification
policy, and methods to validate the certification practice
3.3.19
qualified certificate
certificate whose primary purpose is identifying a person with a high level of assurance in public non-
repudiation services
Note 1 to entry: The actual mechanisms that will decide whether a certificate should or should not be considered
to be a “qualified certificate” in regard to any legislation are outside the scope of this part of ISO 17090.
3.3.20
registration authority
RA
entity that is responsible for identification and authentication of certificate subjects, but that does not
sign or issue certificates (i.e. an RA is delegated certain tasks on behalf of a CA)
[SOURCE: IETF/RFC 3647]
3.3.21
relying party
recipient of a certificate who acts in reliance on that certificate and/or digital signature verified using
that certificate
[SOURCE: IETF/RFC 3647]
3.3.22
third party
party, other than data originator or data recipient, required to perform a security function as part of a
communication protocol
3.3.23
trusted third party
TTP
third party which is considered trusted for purposes of a security protocol
[SOURCE: ENV 13608-1]
Note 1 to entry: This term is used in many ISO/IEC International Standards and other documents describing
mainly the services of a CA. The concept is, however, broader and includes services such as time-stamping and
possibly escrowing.
8 © ISO 2013 – All rights reserved

4 Abbreviations
AA attribute authority
CA certification authority
CP certificate policy
CPS certification practice statement
CRL certificate revocation list
ECG electrocardiogram
EHR electronic health record
PKC public key certificate
PKI public key infrastructure
RA registration authority
TTP trusted third party
5 Healthcare context
5.1 Certificate holders and relying parties in healthcare
For the purposes of facilitating the discussion on digital certificate requirements, the following classes
of actors are introduced. This does not imply that other classes and definitions are not more appropriate
in other contexts.
The focus here is on actors who are directly involved in a health-related communication and may require
a certificate for a PKI-enabled security service. The following actors are defined in 3.1.
Persons: regulated health professional;
non-regulated health professional;
patient/consumer;
sponsored healthcare provider;
supporting organisation employee.
Organisations: healthcare organisation;
supporting organisation.
Other entities: devices;
regulated medical devices;
applications.
In addition to these actors, the wide-scale deployment of digital certificates requires CAs and RAs to be
part of the total system and these organisations become important certificate holders in their own right.
Some healthcare workers are associated with multiple healthcare organisations. There is a primary
need in healthcare to avoid duplicate or redundant registration with its inherent costs and multiplicity
of certificates.
Within the healthcare context, the role of RAs is to identify the actor as either a valid health professional
performing a given role or to identify a consumer as the person with rights to his or her own information.
There also needs to be a way of registering support staff for physicians in private practice (medical
receptionists, billing clerks, file clerks, etc.). Such individuals are not associated with institutions such
as hospitals that are covered by national, state, or provincial health authorities.
5.2 Examples of actors
5.2.1 Regulated health professional
Examples of regulated health professionals are physicians, dentists, registered nurses, and pharmacists.
There are many different classifications of officially regulated/accredited professions in healthcare in
different countries. It is an important task for future ISO standardisation to create a global mapping
for this but, for the purposes of this part of ISO 17090, it is assumed that only very broad classes can be
recognised internationally. In ISO 17090-2, a data structure is presented that allows a broad international
classification to be used in parallel with a more detailed defined classification that may be national or
may follow other jurisdictions, since regulated health professionals are regulated in provinces or states
in some countries.
5.2.2 Non-regulated health professional
Non-regulated health professionals are persons who are employed by a healthcare organisation but
who are not regulated health professionals, and include medical secretaries and record assistants,
transcription clerks (i.e. those who type from a dictated voice recording), billing clerks, and assistant
nurses. For the purpose of this part of ISO 17090, it is important to include the relationship between
the employing healthcare organisation and the employee in a certificate for security services. For the
healthcare professionals, it is important to include the relationship with the professional registration
body in the structure of the digital certificate, but a possible employment or other affiliation of, for
example, a physician may also be important.
There are many different types of roles or occupations of healthcare employees and this part of ISO 17090
makes no attempt to provide a classification scheme.
NOTE The fact that the employee is not registered by a body independent of the employer in his professional
capacity does, of course, not imply that the employee is not professional in conducting his services.
5.2.3 Patient/consumer
The person who receives health-related services is, in most cases, called the patient but, in some
situations, it is more appropriate, in the case of a healthy person and when considering the contractual
relations with the healthcare providers, to call such a person a consumer of health services. Only the
patient/consumer who is also a direct user of a health information system is considered in this context.
5.2.4 Sponsored healthcare provider
There are some types of persons who are providers of health services that are not regulated in the
jurisdiction but who are active in a community and where their professional role may be certified
and sponsored by a registered healthcare organisation. Examples are, in some countries, midwives
(who may be sponsored by obstetricians or other physicians), physiotherapists of different types, and
various persons active in community care for disabled and elderly (who may be sponsored by a general
practitioner or a hospital).
10 © ISO 2013 – All rights reserved

5.2.5 Supporting organisation employee
A supporting organisation employee is a person who is working for a supporting organisation and who
is not a regulated or non-regulated health professional.
5.2.6 Healthcare organisation
Examples of officially registered organisations that have a main activity related to healthcare services
or health promotion are healthcare providers, healthcare financing bodies (insurance companies or
administrators of governmental public health financing), and healthcare research institutions.
5.2.7 Supporting organisation
Supporting organisations perform services for healthcare organisations but do not perform direct
healthcare services.
5.2.8 Devices
Devices are equipment such as ECG machines, laboratory automation equipment, and different portable
diagnostic aids that measure various physiological parameters of a patient; included also are computer
devices such as electronic mail servers, web servers, and application servers.
5.2.9 Applications
Applications are computer software programs running on individual machines and/or networks. Within
the healthcare context, applications relying upon digital certificates could include integrated clinical
management systems, EHR applications, emergency department information systems, imaging systems,
and prescribing, drug profiling, and medication management systems.
5.3 Applicability of digital certificates to healthcare
This part of ISO 17090 applies to the healthcare industry, both within and between jurisdictional
boundaries. It is intended to cover public (government) health authorities and private healthcare
providers across the entire range of settings including hospitals, community health, and general practice.
It also applies to health insurance organisations, healthcare educational institutions, and health-related
activities (such as home care).
While the primary aim is to develop a framework where health professionals, healthcare organisations,
and insurers can securely exchange health information, this part of ISO 17090 is also intended to provide
consumers with the ability to securely access their own healthcare information. Transactions can take
place with CAs and RAs acting as trusted third parties to enable providers, insurers, and consumers
to exchange information, safe in the knowledge that it is secure and protected, and that, if integrity is
breached, it will quickly become known.
Suitable applications of digital certificates within healthcare are:
a) secure electronic mail;
b) access requests by applications used by community-based health professionals for patient
information in hospital-based information systems;
c) access requests by applications used within hospital-based information systems (systems would
include patient administration, clinical management, pathology, radiology, dietary, and other related
information systems);
d) billing applications, which require non-repudiation, message integrity, confidentiality, and
authentication of patients, health service providers, and health insurers, as well as (in some
jurisdictions) fraud prevention;
e) tele-imaging applications, which require a reliable binding between an image and a patient identity,
together with authentication of the health professional;
f) remote access control applications, which have a particular need to verify authenticity, confidentiality,
and integrity;
g) electronic prescription applications, which require all the security services that digital certificates
can offer to check that the prescription is verified as having originated from a particular health
professional (origin authentication) and is being filled for the correct patient (ensuring there are no
errors in transmission requires the integrity service that digital certificates can offer and ensuring
auditability requires the service of non-repudiation);
h) digitally signed patient consent documents;
i) transcription services across national or jurisdictional boundaries;
j) other systems in accordance with local policies.
Local policies may exclude one or more of the above applications from relying upon or otherwise making
use of digital certificates.
A set of scenarios where digital certificates could be applied is detailed in Annex A.
6 Requirements for security services in healthcare applications
6.1 Healthcare characteristics
The healthcare industry has particular security needs that require special interpretation, which is the
reason why this part of ISO 17090 has been developed. Particular characteristics of healthcare are as follows.
a) Health information is reusable and can exist for as long as (and longer than) the person to whom it
refers. This creates a special need for long-term preservation of digital signatures and a valuable
role for the Time Stamp technology that can support this.
b) There are significant health consumer and health service provider concerns to ensure health
information collected is used for health purposes and not for something else, unless the patient has
given his/her explicit consent to use such information (e.g. anonymous patient data may be used for
training and planning purposes).
c) There is a need to improve the health consumers’ confidence in the ability of the health system to
manage their information.
d) There is a need for health professionals and organisations to meet security obligations in the context
of health strategies.
e) The need exists to ensure that health professionals, trading partners, and relying parties making use of
digital certificates have confidence in measures to ensure privacy and security of patient information.
The security issue in healthcare becomes more visible as personal health information is being increasingly
stored using electronic information systems instead of paper files. The first concern of the healthcare
industry is to protect the privacy and safety of the patient. In particular, this concern extends to the
need to comply with relevant privacy legislation, in respect of trans-border health information flows.
If an information system is going to be used by both healthcare professionals and consumers/patients,
it shall be trusted. For this reason, meeting the need for privacy and security is critical for healthcare
information systems.
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6.2 Digital certificate technical requirements in healthcare
6.2.1 General
Major security threats that need to be addressed in healthcare information and communication systems
are unauthorised access gained through stealing the private key of a legitimate certificate holder and
then masquerading as that certificate holder. Such unauthorised access can lead to the healthcare
information itself being altered, lost, or replicated. Digital certificates used in combination with a
security standard, such as ISO/IEC 27002, can significantly reduce the risk of unauthorised access.
Digital certificates provide the only combination of policy, procedures, and technology that offer all
the services of authentication, integrity, confidentiali
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