ITU‐T's Technical Reports and Specifications 687 Anonymization infrastructure and open data in smart sustainable cities Overview ITU‐T Study Group 5 has established a new Focus Group on Smart Sustainable Cities (FG‐SSC) to assess the standardization requirements of cities aiming to boost their social, economic and environmental sustainability through the integration of information and communication technologies (ICTs) in their infrastructures and operations. This Technical Report focus on anonymization infrastructure and open data in smart sustainable cities (SSC), including the demand of open data in SSC, the framework of open data, the handling of open data in SSC, the technology of open data in SSC and the management of open data in SSC. Nevertheless, fruitful application examples are provided as use cases and expected (anonymous) applications of open data in SSC as well as anonymous application for disaster recovery. Executive summary Focus Group on Smart Sustainable Cities (FG‐SSC) has embarked on a journey for integration of open data and adoption of anonymization techniques for future smart sustainable cities. This Technical Report has been specifically written for city officials, town planners, enterprise managers, developers, infrastructure providers, service providers, network operators, and citizens with the ultimate aim of ensuring data protection and improving data availability within their city of interest. Open data is a current movement which requires machine‐readable data to be freely available to everyone to use and republish as they wish, without restrictions of copyright, patents or other mechanisms of control. Currently, the open data system is utilized and is in high demand for creating new services from the level of local community to government. However, in order to beneficially utilize the open data, excessive exposure of private information which maybe included in the open data should be mitigated. Despite this need for protection of certain types of data, there are only few studies on open data utilization for smart sustainable cities (SSC), thereby making it difficult to get a comprehensive understanding of how these types of data can be both utilized and as well as protected. To remedy the lack of credible research on this topic, this document provides a comprehensive study on open data in smart sustainable cities based on six aspects: (i) the demand of open data, (ii) the framework of open data, (iii) open data handling, (iv) the technology of open data, (v) the management of open data and (vi) application examples. In addition, (a) practical methods of open data anonymization, (b) related information for the readers’ understanding that highlight the relationship between open data, anonymization, and (iv) methods of how to utilize the information practically are also provided. The Technical Report further examines the following; (1) definition of the open data and its characteristic features and objectives to understand what types of dangers are predicted, (2) open data framework that provides a general structure to produce and apply open data, (3) related technologies of open data for maintenance and application, (4) management methods of the open data from the aspects of usage, quality, secturity, and operation, (5) use cases of open data driven by governments for smart forecast, city management, metering many types of data with an anonymization technique using information comunication technologies (ICT) infrastructure. Further work will aim to analyse the impacts of open data anonymization and its effectiveness.