ETSI TS 103 532 V1.2.1 (2021-05)

CYBER; Attribute Based Encryption for Attribute Based Access Control

RTS/CYBER-0068

General Information

• Status: Not Published
• Technical Committee: CYBER - Cyber Security
• Current Stage: 12 - Completion
• Due Date: 07-May-2021
• Completion Date: 31-May-2021

Standards Content (Sample)

ETSI TS 103 532 V1.2.1 (2021-05)






TECHNICAL SPECIFICATION
CYBER;
Attribute Based Encryption for
Attribute Based Access Control

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2 ETSI TS 103 532 V1.2.1 (2021-05)

Reference
RTS/CYBER-0068
Keywords
access control, privacy

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3 ETSI TS 103 532 V1.2.1 (2021-05)
Contents
Intellectual Property Rights . 8
Foreword . 8
Modal verbs terminology . 8
1 Scope . 9
2 References . 9
2.1 Normative references . 9
2.2 Informative references . 10
3 Definition of terms, symbols and abbreviations . 12
3.1 Terms . 12
3.2 Symbols . 15
3.3 Abbreviations . 15
4 Attribute-Based Encryption Toolkit . 16
4.1 CPA-secure ciphertext-policy and key-policy attribute-based key-encapsulation mechanisms . 16
4.1.1 Overview . 16
4.1.2 Ciphertext-policy ABKEM . 16
4.1.3 Key-policy ABKEM . 17
4.2 Specifications of CPA-secure ciphertext-policy and key-policy ABKEMs . 17
4.2.1 General . 17
4.2.1.1 Introduction . 17
4.2.1.2 Random bit generation . 18
4.2.1.3 Formats for attributes and policies . 18
4.2.1.4 The map2point mapping . 18
4.2.1.4.1 General . 18
4.2.1.4.2 map2point_34 . 18
4.2.1.4.3 map2point_ssing23 . 19
4.2.1.4.4 map2point_23 . 19
4.2.1.5 Monotone span programs . 20
4.2.1.5.1 General . 20
4.2.1.5.2 MSP_Encode . 20
4.2.1.5.3 MSP_Decode . 21
4.2.2 Specification of CP-WATERS-KEM . 22
4.2.2.1 General . 22
4.2.2.2 Setup . 22
4.2.2.3 Secret-key generation . 22
4.2.2.4 Symmetric-key encapsulation . 23
4.2.2.5 Symmetric-key decapsulation . 24
4.2.3 Specification of CP-FAME-KEM and KP-FAME-KEM . 24
4.2.3.1 Hash functions . 24
4.2.3.2 Setup for CP-FAME-KEM and KP-FAME-KEM . 25
4.2.3.3 CP-FAME-KEM . 26
4.2.3.3.1 General . 26
4.2.3.3.2 Secret-key generation . 26
4.2.3.3.3 Symmetric-key encapsulation . 27
4.2.3.3.4 Symmetric-key decapsulation . 27
4.2.3.4 KP-FAME-KEM . 28
4.2.3.4.1 General . 28
4.2.3.4.2 Secret-key generation . 28
4.2.3.4.3 Symmetric-key encapsulation . 29
4.2.3.4.4 Symmetric-key decapsulation . 30
4.2.4 Specification of KP-GSPW-KEM . 30
4.2.4.1 General . 30
4.2.4.2 Setup . 31
4.2.4.3 Secret-key generation . 31
4.2.4.4 Symmetric-key encapsulation . 32
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4 ETSI TS 103 532 V1.2.1 (2021-05)
4.2.4.5 Symmetric-key decapsulation . 32
4.3 Ciphertext-Policy and Key-Policy Attribute-Based Encryption . 33
4.3.1 Overview . 33
4.3.2 Ciphertext-policy ABE . 33
4.3.3 Key-Policy ABE . 33
4.4 Specifications of CPA-secure ciphertext-policy and key-policy ABE . 34
4.4.1 General . 34
4.4.1.1 Introduction . 34
4.4.1.2 Pseudorandom generator . 34
4.4.2 CPA-secure CP-ABE . 34
4.4.3 CPA-secure KP-ABE scheme . 35
4.5 Specifications of CCA-secure CP-ABKEMs and KP-ABKEMs, CP-ABE schemes and KP-ABE
schemes . 36
4.5.1 General . 36
4.5.1.1 Introduction . 36
4.5.1.2 Collusion-resistant hash function . 36
4.5.1.3 Authenticated encryption . 36
4.5.2 CCA-secure CP-ABKEM . 36
4.5.3 CCA-secure KP-ABKEM . 37
4.5.4 CCA-secure CP-ABE . 38
4.5.5 CCA-secure KP-ABE . 38
4.6 Requirements for compliant ABKEMs . 39
4.6.1 General . 39
4.6.2 Requirement 1: correctness and indistinguishability under chosen-plaintext attacks for ABKEMs . 39
4.6.2.1 Correctness . 39
4.6.2.2 Indistinguishability under chosen-plaintext attacks . 40
4.6.3 Requirement 2: Sufficient security levels . 41
4.7 Revocation . 41
4.7.1 Attribute revocation . 41
4.7.2 Secret-key revocation . 41
4.8 Recommendations . 41
4.8.1 Overview . 41
4.8.2 Efficiency considerations . 42
4.8.3 Security considerations . 42
5 Trust models . 42
5.1 Overview . 42
5.2 Roles . 42
5.2.1 Data Consumer . 42
5.2.2 Data Controller . 42
5.2.3 Data Processor . 43
5.2.4 Data Subject . 43
5.2.5 Device manager . 43
5.2.6 Platform Provider (PP). 43
5.2.7 Third Party Service Provider (3SP) . 43
5.2.8 Platform User (Pu) . 43
5.3 Models . 43
5.3.1 Long term storage . 43
5.3.2 Offline access control . 44
5.3.3 Platform Provider . 45
5.4 Functions . 46
5.4.1 Authority function . 46
5.4.2 Assertion function . 46
5.4.2.1 General . 46
5.4.2.2 Data access assertion . 46
5.4.2.3 Data capture assertion . 46
5.4.3 Encryption function . 46
5.4.4 Policy Management function . 47
5.4.5 Key distribution function . 47
5.4.6 Decryption function . 47
6 Procedures for distributing attributes and keys . 47
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5 ETSI TS 103 532 V1.2.1 (2021-05)
6.1 Introduction . 47
6.2 Platform Provider extended with Public Key Infrastructure X.509 . 48
6.2.1 Overview . 48
6.2.2 Entities . 48
6.2.2.1 Introduction . 48
6.2.2.2 ABE Authority (ABEA) . 48
6.2.2.3 Keys associated to the Third Party Service Provider (3SP) . 49
6.2.2.4 Keys associated to the Platform Provider (PP) . 49
6.2.3 ABE Key Distribution . 49
6.2.3.1 General . 49
6.2.3.2 Setup . 49
6.2.3.3 ABE Public Key distribution. 50
6.2.3.4 ABE secret key material distribution . 50
6.2.3.5 Attributes distribution . 50
6.2.4 ABE Public Key revocation . 50
6.3 Assertions . 50
6.3.1 Introduction. 50
6.3.2 Types of assertions. 50
6.3.3 Mapping to SAML . 51
6.3.3.1 SAML Attributes . 51
6.3.3.2 SAML Attribute Statements . 51
6.3.3.2.1 Unencrypted format . 51
6.3.3.2.2 Encrypted format . 52
6.3.3.3 SAML Attribute Queries . 52
6.3.3.4 Key assertions . 52
6.3.3.5 Security considerations . 52
6.3.4 SAML binding for CoAP . 52
6.3.4.1 Message encapsulation . 52
6.3.4.2 Addressing and intermediaries . 52
6.3.4.3 Security . 53
7 Attribute Based Access Control layer . 53
7.1 Overview . 53
7.2 Base ABKEM access control capabilities ("Layer 1") . 53
7.2.1 Introduction. 53
7.2.2 Attributes . 53
7.2.2.1 Syntax for attribute declaration . 53
7.2.2.2 Attribute types . 54
7.2.2.3 Syntax for ABKEM universe declaration . 54
7.2.2.4 Syntax for value assignment in annotations . 54
7.2.3 Policies . 55
7.2.3.1 General definition of a policy and syntax . 55
7.2.3.2 Relational statements . 55
7.2.3.2.1 Introduction . 55
7.2.3.2.2 Relational operators for the unsigned integer attribute type . 55
7.2.3.2.3 Relational operators for the boolean attribute type . 56
7.2.3.2.4 Relational operators for the string attribute type . 56
7.2.3.3 Logical operators . 56
7.2.3.4 Threshold gates . 56
7.2.3.5 Top-level statements . 57
7.2.4 ABKEM bindings . 57
7.2.4.1 Introduction . 57
7.2.4.2 Binding rules for value assignment to attributes in annotation . 57
7.2.4.2.1 Common translation rules . 57
7.2.4.2.2 Unsigned integer . 57
7.2.4.2.3 Boolean . 58
7.2.4.2.4 String . 58
7.2.4.3 Binding rules for policy translation . 58
7.2.4.3.1 Common translation rules . 58
7.2.4.3.2 Integer . 59
7.2.4.3.3 Boolean . 62
7.2.4.3.4 String . 62
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6 ETSI TS 103 532 V1.2.1 (2021-05)
7.3 Intermediate access control layer ("Layer 2") . 63
7.3.1 Introdu
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