ISO/IEC 27034-7:2018

Information technology -- Application security

This document describes the minimum requirements when the required activities specified by an Application Security Control (ASC) are replaced with a Prediction Application Security Rationale (PASR). The ASC mapped to a PASR define the Expected Level of Trust for a subsequent application. In the context of an Expected Level of Trust, there is always an original application where the project team performed the activities of the indicated ASC to achieve an Actual Level of Trust. The use of Prediction Application Security Rationales (PASRs), defined by this document, is applicable to project teams which have a defined Application Normative Framework (ANF) and an original application with an Actual Level of Trust. Predictions relative to aggregation of multiple components or the history of the developer in relation to other applications is outside the scope of this document.

Technologies de l'information -- Sécurité des applications

General Information

• Status: Published
• Publication Date: 21-May-2018
• ICS: 35.030 - IT Security
• ICS: 35.040 - Information coding
• Technical Committee: ISO/IEC JTC 1/SC 27 - Information security, cybersecurity and privacy protection
• Drafting Committee: ISO/IEC JTC 1/SC 27/WG 4 - Security controls and services
• Current Stage: 6060 - International Standard published
• Start Date: 04-May-2018
• Completion Date: 22-May-2018

Standards Content (sample)

INTERNATIONAL ISO/IEC
STANDARD 27034-7
First edition
2018-05
Information technology — Application
security —
Part 7:
Assurance prediction framework
Technologies de l'information — Sécurité des applications —
Partie 7: Cadre de l'assurance d'une prédiction
Reference number
ISO/IEC 27034-7:2018(E)
ISO/IEC 2018
---------------------- Page: 1 ----------------------
ISO/IEC 27034-7:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2018

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO/IEC 2018 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 27034-7:2018(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

0 Introduction .............................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Abbreviated terms .............................................................................................................................................................................................. 3

5 Prediction concepts ........................................................................................................................................................................................... 3

5.1 Goal of prediction ................................................................................................................................................................................. 3

5.2 Prediction framework ....................................................................................................................................................................... 4

5.3 Expected Level of Trust ................................................................................................................................................................... 4

5.3.1 Concept .................................................................................................................................................................................... 4

5.3.2 Expected level of trust in the ONF .................................................................................................................... 5

5.3.3 Expected level of trust in the ANF ..................................................................................................................... 6

5.3.4 ASC data in the ANF ....................................................................................................................................................... 7

5.3.5 Expected level of trust over sequence of application versions ................................................ 8

5.4 Principles ..................................................................................................................................................................................................10

5.4.1 ISO/IEC 27034-1 principles ................................................................................................................................10

5.4.2 Appropriate investment for application security principle .....................................................10

5.4.3 Application security should be demonstrated principle ............................................................10

5.5 Prediction authorization .............................................................................................................................................................10

5.5.1 Prediction accountability ......................................................................................................................................10

5.5.2 Forced authorization .................................................................................................................................................11

5.6 Claims relative to the actual level of trust ....................................................................................................................11

6 Predictions ...............................................................................................................................................................................................................11

6.1 Prediction initiator ...........................................................................................................................................................................11

6.2 Prediction circumstances............................................................................................................................................................12

6.2.1 Typical circumstance ................................................................................................................................................12

6.2.2 Relationship to level of trust ...............................................................................................................................12

6.3 Prediction consumer .......................................................................................................................................................................12

7 Substantial changes ........................................................................................................................................................................................13

7.1 Definition discussion ......................................................................................................................................................................13

7.2 Guidance for substantial changes risk analysis .......................................................................................................13

7.2.1 General...................................................................................................................................................................................13

7.2.2 Code change and static analysis.......................................................................................................................13

7.2.3 Architectural review ..................................................................................................................................................14

7.2.4 Deprecation of tests over time ..........................................................................................................................14

8 Confidence ................................................................................................................................................................................................................14

8.1 Confidence building blocks .......................................................................................................................................................14

8.2 Establishing confidence................................................................................................................................................................14

9 Prediction application security rationale ...............................................................................................................................15

9.1 Linkage to ASC ......................................................................................................................................................................................15

9.2 Components ............................................................................................................................................................................................15

9.3 Format .........................................................................................................................................................................................................16

9.3.1 Identifiers, actors, ASCs outcomes ................................................................................................................16

9.3.2 Rationale ..............................................................................................................................................................................16

9.3.3 Duplication of information ...................................................................................................................................16

9.3.4 Assurance cases .............................................................................................................................................................16

9.4 Approval by ONF Committee ...................................................................................................................................................16

9.5 Use of RACI charts in description of activities, roles, and responsibilities ......................................17

10 PASR audit.................................................................................................................................................................................................................17

© ISO/IEC 2018 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/IEC 27034-7:2018(E)

10.1 Auditing linkage ..................................................................................................................................................................................17

10.2 Auditing actual level of trust ....................................................................................................................................................17

10.3 Auditing expected level of trust .............................................................................................................................................17

10.4 PASR quality ...........................................................................................................................................................................................18

11 PASR Verification ...............................................................................................................................................................................................18

11.1 Validation ..................................................................................................................................................................................................18

11.2 Verification ..............................................................................................................................................................................................18

11.3 Expected results ..................................................................................................................................................................................18

11.4 Missing state ..........................................................................................................................................................................................18

11.4.1 Inability to generate verification measurements .............................................................................18

11.4.2 Example ................................................................................................................................................................................18

12 PASR implementation ...................................................................................................................................................................................19

12.1 Prediction framework ....................................................................................................................................................................19

12.2 Steps to implement a PASR ........................................................................................................................................................19

12.2.1 General...................................................................................................................................................................................19

12.2.2 Actor responsibilities ................................................................................................................................................20

12.3 ONF feedback ........................................................................................................................................................................................20

13 Expected level of trust report ...............................................................................................................................................................20

13.1 Purpose .......................................................................................................................................................................................................20

13.2 Components ............................................................................................................................................................................................20

13.3 Format .........................................................................................................................................................................................................21

13.4 History, assumptions and social history ........................................................................................................................21

Annex A (informative) Expected level of trust assurance case ...............................................................................................23

Annex B (informative) Comparison of ASC to PASR ............................................................................................................................25

Bibliography .............................................................................................................................................................................................................................29

iv © ISO/IEC 2018 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/IEC 27034-7:2018(E)
Foreword

ISO (the International Organization for Standardization) and IEC (the International Electrotechnical

Commission) form the specialized system for worldwide standardization. National bodies that are

members of ISO or IEC participate in the development of International Standards through technical

committees established by the respective organization to deal with particular fields of technical

activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international

organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the

work. In the field of information technology, ISO and IEC have established a joint technical committee,

ISO/IEC JTC 1.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for

the different types of document should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject

of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent

rights. Details of any patent rights identified during the development of the document will be in the

Introduction and/or on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/IEC JTC 1, Information technology,

Subcommittee SC 27, Security techniques.
A list of all parts in the ISO/IEC 27034 series can be found on the ISO website.
© ISO/IEC 2018 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/IEC 27034-7:2018(E)
0 Introduction
0.1 Basic prediction

The project team declares an application secure when the supporting evidence demonstrates the

attainment of the Targeted Level of Trust (ISO/IEC 27034-1:2011, 0.4.4). A security prediction occurs

when the project team uses the supporting evidence from a previous version of the application and

provides a rationale as to why the supporting evidence is still valid for the subsequent application.

The security prediction framework is the process whereby organizations, who use ISO/IEC 27034 (all

parts), perform risk analysis and document decisions made, relative to Application Security Controls

(ASCs) performed on a previous version of an application but not performed on the current version. All

such predictions are fundamentally subjective, and at best can only express a degree of confidence.

Today, individuals and organizations already transfer their confidence in security claims between

versions of applications without any strong rationale supporting this transfer. Making a security

prediction for a subsequent application, without any rationale or justification, is inherently a bad

practice. To rectify this situation, this document establishes a framework by codifying requirements

for making security predictions between versions of an application.

This document focuses on predictions, or claim transfers, related to subsequent versions of the same

application.
0.2 Purpose

The purpose of this document is to help organizations to develop and use Prediction Application

Security Rationales (PASR) in disseminating information relative to security properties of multiple

versions of the same application by:

a) providing additional guidance to Organization Normative Framework (ONF) Committees so that

they can set up appropriate guidelines for when predictions are and are not appropriate for their

organizations;

b) providing the results of a risk analysis that contains the rationale as to why the changes in the

subsequent application are not substantial;

c) applying to application projects that are using an Application Normative Framework (ANF);

d) indicating the Actual Level of Trust for the original and subsequent applications;

e) indicating the Expected Level of Trust for the original, if used, and subsequent applications;

f) providing the rationale as to why the risk analysis, predictions for individual Application Security

Control (ASC), and the Actual Level of Trust together produce the Expected Level of Trust; and

g) verifying a PASR when the auditor chooses to rerun the corresponding ASC verification activity.

This document does not provide guidelines on:
a) what is and is not an appropriate risk;
b) what is and is not substantial change;
c) when an application owner should or should not accept a specific risk; or
d) when an acquirer should or should not accept an Expected Level of Trust.
vi © ISO/IEC 2018 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/IEC 27034-7:2018(E)
0.3 Targeted audience
0.3.1 General

The following audiences find values and benefits when carrying their designated organizational roles:

a) managers;
b) ONF Committees;
c) project teams;
d) domain experts;
e) auditors;
f) application owners; and
g) acquirers.
0.3.2 Managers
The manager roles are the same as in ISO/IEC 27034-1:2011, 0.3.2.
0.3.3 ONF Committee

As described in ISO/IEC 27034-1:2011, 3.17, the ONF Committee is responsible for managing the

implementation and maintenance of the application-security-related components and processes in the

Organization Normative Framework. The ONF Committee:

a) provides guidelines to project teams as to what is and is not a substantial change;

b) evaluates, and documents, in the ASC, the risk of choosing the PASR over performing the ASC

activity;

c) reviews each ASC and determines if predictions are allowed and, if allowed, under what

circumstances predictions are appropriate;
d) documents the prediction determination in each ASC in the ONF;

e) advises the application owner, when establishing the ANF, the estimated risk of using the PASR; and

f) responds to requests from project teams to modify the prediction guidelines for specific ASC.

0.3.4 Provisioning and operation team

As described in ISO/IEC 27034-1:2011, 0.3.3, members of provisioning and operation teams (known

collectively as the project team) are individuals involved in an application’s design, development and

maintenance throughout its whole life cycle. The project manager is responsible for managing the ANF.

The project team:

a) performs a risk analysis on the proposed changes to the application to determine if the changes are

substantial;

b) creates the PASR (as defined in 3.2) for each ASC for which there is a prediction; and

c) generates the Expected Level of Trust report.
© ISO/IEC 2018 – All rights reserved vii
---------------------- Page: 7 ----------------------
ISO/IEC 27034-7:2018(E)
0.3.5 Domain experts

An individual who is an expert in a particular domain, area, or topic that provides specific knowledge

or expertise to the project team. These experts:
a) assist the project team in making an accurate risk assessment; and

b) assist the project team in making the determination if the changes to the application represent a

substantial change.
0.3.6 Auditors

As described in ISO/IEC 27034-1:2011, 0.3.6, auditors are personnel performing roles in the audit

process who participate in application verification.
0.3.7 Application owners

Based on the definition in ISO/IEC 27034-1:2011, 3.6, the application owner is the organization’s

representative who is responsible and accountable for the security and the protection of an application.

Application owners make the final decisions on:

a) acceptance of the project team risk analysis that the changes to the application are not substantial;

b) approval of a set of ASCs for which the project team generates PASRs; and
c) acceptance of the Expected Level of Trust.
0.3.8 Acquirers

This includes all individuals involved in acquiring a product or service. Acquirers:

a) perform actions as per ISO/IEC 27034-1:2011, 0.3.4;

b) evaluate if the Actual Level of Trust for the original application is appropriate to mitigate the risks

the acquirer anticipates for the expected contexts the acquirer will use the application in;

c) evaluate if the Expected Level of Trust for the subsequent application is appropriate to mitigate the

risks the acquirer anticipates for the expected contexts the acquirer will use the application in; and

d) evaluate if the rationale that changes to the subsequent application are not substantial and, if not in

agreement with the rationale, determine if additional verification is necessary.
viii © ISO/IEC 2018 – All rights reserved
---------------------- Page: 8 ----------------------
INTERNATIONAL STANDARD ISO/IEC 27034-7:2018(E)
Information technology — Application security —
Part 7:
Assurance prediction framework
1 Scope

This document describes the minimum requirements when the required activities specified by an

Application Security Control (ASC) are replaced with a Prediction Application Security Rationale

(PASR). The ASC mapped to a PASR define the Expected Level of Trust for a subsequent application. In

the context of an Expected Level of Trust, there is always an original application where the project team

performed the activities of the indicated ASC to achieve an Actual Level of Trust.

The use of Prediction Application Security Rationales (PASRs), defined by this document, is applicable

to project teams which have a defined Application Normative Framework (ANF) and an original

application with an Actual Level of Trust.

Predictions relative to aggregation of multiple components or the history of the developer in relation to

other applications is outside the scope of this document.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO/IEC 27000, Information technology — Security techniques — Information security management

systems — Overview and vocabulary

ISO/IEC 27034-1, Information technology — Security techniques — Application security — Part 1:

Overview and concepts
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/IEC 27000, ISO/IEC 27034-1

and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
prediction

statement or estimate that a specific thing will happen in the future or will be a consequence of

something

Note 1 to entry: The origin of the word is early 17th century: from Latin praedict-“made known beforehand,

declared”, from the verb praedicere from prae-“beforehand” + dicere “say”.

Note 2 to entry: The use in this document reflects the expectation that, if the security and verification

measurement activities are executed, they will match the results from the original application.

© ISO/IEC 2018 – All rights reserved 1
---------------------- Page: 9 ----------------------
ISO/IEC 27034-7:2018(E)
3.2
prediction framework

process that performs a risk analysis, establishes an Expected Level of Trust (3.8), assigns Application

Security Control verification to a PASR (3.7), and then creates an Expected Level of Trust Report (3.9)

3.3
original application
application that establishes the baseline Actual Level of Trust

Note 1 to entry: The original application is not necessarily version 1.0 and, hence, can have an associated

Expected Level of Trust.
3.4
subsequent application
application related to the original application (3.3) through versioning
EXAMPLE Version 1 to version 1.1.
3.5
predictive security

transfer of confidence in the security claims (3.6) of the original application (3.3) to the security claims

of the subsequent application (3.4)
3.6
security claim
specific claim that security properties are present in an application

Note 1 to entry: Under the ISO/IEC 27034 frameworks (all parts), it is the claim that the activities specified by an

Application Security Control mitigate specific security risks to an acceptable level.

Note 2 to entry: In the context of a PASR, it is the claim that verification of the Application Security Control

activities, which were predicted by the PASR, would produce the same results as if the Application Security

Control activities were performed.
3.7
Prediction Application Security Rationale
PASR

rationale for a prediction (3.1), supported by risk analysis documents, approved by the application

owner, explaining that performing the verification activities of a specific Application Security Control

is not necessary

Note 1 to entry: Use of PASR requires approval of both application owner and the inclusion of the PASR guidelines

in the Application Security Control by the Organization Normative Framework Committee.

3.8
Expected Level of Trust

level of trust, defined in the Organization Normative Framework, where the activities of some of the

Application Security Controls are satisfied through the creation of a PASR (3.7)

Note 1 to entry: This document describes the minimum requirements applicable to the Application Security

Controls used in an Expected Level of Trust for a subsequent application (3.4). In the context of an Expected

Level of Trust, there is always an original application (3.3) where the project team performed the activities of the

indicated Application Security Controls.
3.9
Expected Level of Trust Report

document presenting and supporting the risk analysis in support of predictions (3.1) made for a

subsequent application
...