ISO/IEC 18033-2:2006

Information technology — Security techniques — Encryption algorithms — Part 2: Asymmetric ciphers

ISO/IEC 18033-2:2006 specifies encryption systems (ciphers) for the purpose of data confidentiality. The primary purpose of encryption (or encipherment) techniques is to protect the confidentiality of stored or transmitted data. An encryption algorithm is applied to data (often called plaintext or cleartext) to yield encrypted data (or ciphertext); this process is known as encryption. The encryption algorithm should be designed so that the ciphertext yields no information about the plaintext except, perhaps, its length. Associated with every encryption algorithm is a corresponding decryption algorithm, which transforms ciphertext back into its original plaintext. An asymmetric, i.e. public-key, encryption scheme allows a sender to use a recipient's public key to transmit an encryption of a message to the receiver, who can use his secret key to decrypt the given ciphertext, thereby obtaining the original message. Such a scheme should be secure in the sense that no information about the message should be leaked to a (resource-bounded) attacker, even if that attacker mounts a so-called 'chosen ciphertext' attack, in which he may obtain decryptions of other ciphertexts. This is the strongest type of attack that has been proposed for a public-key encryption scheme. ISO/IEC 18033-2:2006 specifies the functional interface of such a scheme, and in addition specifies a number of particular schemes that appear to be secure against chosen ciphertext attack. The different schemes offer different trade-offs between security properties and efficiency.

Technologies de l'information — Techniques de sécurité — Algorithmes de chiffrement — Partie 2: Chiffres asymétriques

General Information

• Status: Published
• Publication Date: 07-May-2006
• 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 2 - Cryptography and security mechanisms
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 03-May-2024

Relations

• Consolidated By: ISO 11148-3:2012 - Hand-held non-electric power tools — Safety requirements — Part 3: Drills and tappers
• Effective Date: 06-Jun-2022
• Amended By: ISO/IEC 18033-2:2006/Amd 1:2017 - Information technology — Security techniques — Encryption algorithms — Part 2: Asymmetric ciphers — Amendment 1: FACE
• Effective Date: 25-Dec-2021

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 18033-2
First edition
2006-05-01

Information technology — Security
techniques — Encryption algorithms —
Part 2:
Asymmetric ciphers
Technologies de l'information — Techniques de sécurité — Algorithmes
de chiffrement —
Partie 2: Chiffres asymétriques




Reference number
ISO/IEC 18033-2:2006(E)
©
ISO/IEC 2006

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ISO/IEC 18033-2:2006(E)
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ISO/IEC 18033-2:2006(E)
Contents Page

1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 De¯nitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4 Symbols and notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 Mathematical conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.1 Functions and algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5.2 Bit strings and octet strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.3 Finite Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.4 Elliptic curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6 Cryptographic transformations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1 Cryptographic hash functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.2 Key derivation functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.3 MAC algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.4 Block ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.5 Symmetric ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7 Asymmetric ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.1 Plaintext length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7.2 The use of labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.3 Ciphertext format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.4 Encryption options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.5 Method of operation of an asymmetric cipher . . . . . . . . . . . . . . . . . . . 22
7.6 Allowable asymmetric ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8 Generic hybrid ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8.1 Key encapsulation mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
8.2 Data encapsulation mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . 24
8.3 HC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
9 Constructions of data encapsulation mechanisms . . . . . . . . . . . . . . . . . . . . 26
9.1 DEM1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.2 DEM2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
9.3 DEM3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
10 ElGamal-based key encapsulation mechanisms . . . . . . . . . . . . . . . . . . . . . 30
10.1 Concrete groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
...