What is this ISO/IEC 15946‑5 - Cryptographic techniques based on elliptic curves about?
ISO/IEC 15946‑5 discusses information security and cryptographic techniques based on elliptic curves with a focus on elliptic curve generation. ISO/IEC 15946‑5 is the fifth part of the ISO/IEC 15946 multi-series on information security that specifies public-key cryptographic techniques based on elliptic curves described in ISO/IEC 15946‑1.
ISO/IEC 15946‑5 defines elliptic curve generation techniques useful for implementing the elliptic curve based mechanisms defined in ISO/IEC 29192‑4, ISO/IEC 9796‑3, ISO/IEC 11770‑3, ISO/IEC 14888‑3, ISO/IEC 18033‑2, and ISO/IEC 18033‑5.
ISO/IEC 15946‑5 is applicable to cryptographic techniques based on elliptic curves defined over finite fields of prime power order (including the special cases of prime order and characteristic two).
Note: ISO/IEC 15946‑5 is not applicable to the representation of elements of the underlying finite field (i.e., which basis is used).
Who is ISO/IEC 15946‑5 - Cryptographic techniques based on elliptic curves for?
ISO/IEC 15946‑5 on cryptographic techniques based on elliptic curves is useful for:
- Cryptographers
- Writing Experts
- Government and law enforcement agencies
Why should you use ISO/IEC 15946‑5 - Cryptographic techniques based on elliptic curves?
The security of such a public-key system depends on the difficulty of determining discrete logarithms in the group of points of an elliptic curve. With current knowledge, this problem is much harder than the factorization of integers or the computation of discrete logarithms in a finite field.
It is possible for elliptic curve based public-key systems to use much shorter parameters than the RSA system or the classical discrete logarithm-based systems that make use of the multiplicative group of a finite field. This yields significantly shorter digital signatures and system parameters.
The purpose of ISO/IEC 15946‑5 is to meet the increasing interest in elliptic curve based public-key technology by describing elliptic curve generation methods to support key management, encryption, and digital signatures based on an elliptic curve.
What’s changed since the last update?
BS ISO/IEC 15946‑5:2022 supersedes ISO/IEC 15946‑5:2017, which is withdrawn. BS ISO/IEC 15946‑5:2022 includes some technical changes with respect to ISO/IEC 15946‑5:2017.
These include:
- BLS curves have been added to Clause 7
- Security background for pairing-friendly curves has been added to Annex B, including the exTNFS attack that affects the security of numerical examples of BN curves
- Except for BN curves, all other curves have been moved to Annex C
- Associated numerical examples (Annex D) and properties (Annex E) have been updated

