The co-existence of Internet protocol suites and packet-switching technologies emerging in the late 1960s and early 1970s are an endless stream of research concerns for the security and privacy of various Web services. However, the majority of existing web services are deployed on centralized servers, which includemany components of private data, and consequently they provide attackers a single target to hack. Another problem is related to data integrity, for example, users’ personal information is commonly saved in centralized databases, which can be easily and silentlytampered withif detailedauditing is not enabled. Furthermore, high maintenance service fees may restrict the development of web services. Based on the existing problems regarding security and scalability, we can see building trustworthy web services is a very important research topic needed to address the current challenges, especially for large-scale web services. At present, blockchain technology has shown its potential for solving and enhancing the traditional solutions in tamper proof transactions, decentralized and distributed processing, privacy protection and so on in many applications. In this paper, we conceptualize a blockchain-based architecture for web services based on multiple tiers, including data, network, consensus, application and contract tiers. The architecturesupports the addition or modification of various web services based on consensus protocols without relying on any third-parties or institutions, and the privacy of users can also be guaranteed in a decentralized manner.  Furthermore, we reviewed the security mechanisms through different aspects to analyse and summarize the concrete technical requirements needed to integratea blockchain-based solution with web services. Finally, a case study about knowledge maintenance is demonstrated to explain the blockchain-based solution and future challenges that arise.  The main aim of our research is to analyse a blockchain-based solution for web services, and to guide future implementations, including, for example,the design ofthe block and blockchain structure, consensus protocol improvements, smart contract deployment and other technical aspects associated with blockchains.