This Recommendation | International Standard supplements Rec. ITU-T X.509 | ISO/IEC 9594-8 and Rec. ITU-T X.510 | ISO/IEC 9594-11 by providing an extended description of cryptographic algorithms and guidance in establishment and maintenance of a public-key infrastructure (PKI).

It is outside the scope of this Recommendation | International Standard to define new cryptographic algorithms, but it is within scope to discuss already-defined cryptographic algorithms that provide optimal protection, including future protection against attacks using powerful quantum computers.

This Recommendation | International Standard specifies how public-key infrastructure (PKI) may be adapted to support machine-to-machine (M2M) communication, e.g., smart grid and Internet of things (IoT), to allow interworking.

This Recommendation | International Standard specifies the procedures for establishment and maintenance of a PKI supporting new areas, such as intelligent electricity network (smart grid) and industrial Internet of things.