This publication explains ITU's role in cybersecurity. ITU's Standardization Sector (ITU-T) holds a unique position in the field of standardization: its work brings together the private sector and governments to coordinate work and promote the harmonization of security policy and security standards on an international scale. Standardization can help guarantee established levels of performance and security in technologies, systems and products and help provide businesses with a systematic approach to information security. Manufacturers and service providers can be sure that their concerns have been reviewed in consultation with leading experts in the field in reaching the standard approach or processes needed to achieve minimum levels of performance. As well as many key security Recommendations, ITU has developed overview security requirements, security guidelines for protocol authors, guidance on how to identify cyberthreats and countermeasures to mitigate risks. ITU's work on security covers a broad range of activities in security from network attacks, theft or denial of service, theft of identity, eavesdropping, tele-biometrics for authentication, security for emergency telecommunications and telecommunication network security requirements.