ISO IEC 10118-3-2018 PDF

Full title and description

IT Security techniques — Hash-functions — Part 3: Dedicated hash-functions. This international standard specifies a set of dedicated (specially designed) cryptographic hash‑functions, their round‑functions, padding, initialization values, parameters and object identifiers; it also includes numerical examples and informative annexes (including SHA‑3 XOFs).

Abstract

This document specifies dedicated hash‑functions based on the iterative use of a round‑function; distinct round‑functions give rise to distinct dedicated hash‑functions. The standard also notes that use of Dedicated Hash‑Functions 1, 2 and 3 in new digital‑signature implementations is deprecated because of short hash lengths and/or cryptanalytic results; numerical examples and SHA‑3 extendable‑output functions are provided in annexes.

General information

• Status: Published (International Standard, confirmed in systematic review).
• Publication date: October 2018 (published 2018‑10; publication actions completed 2018‑10‑31).
• Publisher: International Organization for Standardization / International Electrotechnical Commission (ISO/IEC), JTC 1/SC 27.
• ICS / categories: 35.030 (IT security / information security).
• Edition / version: Edition 4 (ISO/IEC 10118-3:2018).
• Number of pages: 398 pages.

Scope

Specifies the design and normative details for dedicated cryptographic hash‑functions (round‑functions, padding, initial values, constants and object identifiers), provides computation examples and informative annexes (including SHA‑3 XOFs). It standardizes a set of named/numbered dedicated hash‑functions for use in security protocols and related applications, while warning about legacy algorithms that lack sufficient collision resistance for new digital‑signature uses.

Key topics and requirements

• Normative specification of dedicated hash‑functions: round‑functions, padding rules, initialization vectors, constants and OIDs.
• Includes a catalog of widely used dedicated functions (examples include RIPEMD‑160/128, SHA‑1, SHA‑2 family, WHIRLPOOL, STREEBOG, SM3, SHA‑3 family and related truncated/derived variants and XOFs) for interoperable implementation.
• Deprecation guidance: Dedicated Hash‑Functions 1–3 are deprecated for new digital‑signature implementations because of short output lengths and cryptanalytic weaknesses; they remain allowed for legacy or non‑collision‑resistant uses (e.g., some MAC or KDF contexts).
• Informative material: numerical computation examples (Annex B) and SHA‑3 extendable‑output function details (Annex C) to aid implementers.
• Interoperability and algorithm mapping guidance for use with related standards (e.g., MAC and KDF standards specify permitted combinations with these dedicated hash‑functions).

Typical use and users

Primarily used by cryptographic library authors, protocol designers, security engineers, implementers of digital‑signature, message‑authentication and key‑derivation functions, standards bodies and conformity assessors. It is consulted when an implementer needs authoritative, interoperable definitions (including OIDs and test examples) for the named hash functions included in the standard.

Related standards

Belongs to the ISO/IEC 10118 family (hash‑function standards). It is commonly referenced together with message authentication and key management standards such as ISO/IEC 9797‑2 (MACs) and ISO/IEC 11770‑6 (KDFs), which define permissible uses and mappings between MAC/KDF algorithms and the dedicated hash‑functions in this part.

Keywords

hash function, dedicated hash, RIPEMD, SHA‑1, SHA‑2, SHA‑3, WHIRLPOOL, STREEBOG, SM3, XOF, padding, round‑function, OID, IT security, ISO/IEC 10118

FAQ

Q: What is this standard?

A: ISO/IEC 10118‑3:2018 is Part 3 of the ISO/IEC 10118 series; it gives normative specifications for dedicated cryptographic hash‑functions (their compression/round functions, padding, initial values, constants and object identifiers) and provides examples and informative annexes.

Q: What does it cover?

A: It covers the formal algorithmic descriptions and parameters for a set of dedicated hash‑functions (several legacy and modern algorithms), numerical examples, and guidance on suitable uses — including a deprecation notice for some short/weak functions for new digital‑signature applications.

Q: Who typically uses it?

A: Cryptographic library developers, protocol and security engineers, evaluators, implementers of MACs and KDFs, and standards or regulatory bodies that require canonical algorithm definitions and OIDs for interoperability.

Q: Is it current or superseded?

A: The 2018 edition (Edition 4) is the current published edition; the ISO record shows the publication in October 2018 and that the standard was reviewed and confirmed in 2024, so it remains current as of that confirmation.

Q: Is it part of a series?

A: Yes — it is Part 3 of the ISO/IEC 10118 series on hash‑functions (Part 1: general definitions; Part 2: block‑cipher‑based hash constructions; Part 3: dedicated hash‑functions; other parts cover additional constructions).

Q: What are the key keywords?

A: Hash functions, dedicated hash, RIPEMD, SHA‑1, SHA‑2, SHA‑3, WHIRLPOOL, STREEBOG, SM3, XOF, OID, padding, round‑function.