The Internet of Things (IoT) is bringing new ways to collect and analyze data to develop applications answering or anticipating users' needs. These data may be privacy-sensitive, requiring ecient privacypreserving mechanisms. The IoT is a distributed system of unprecedented scale, creating challenges for performance and security. Classic blockchains could be a solution by providing decentralization and strong security guarantees. However, they are not ecient and scalable enough for large scale IoT systems, and available tools designed for preserving privacy in blockchains, e.g. coin mixing, have a limited eect due to high transaction costs and insucient transaction rates. This article provides a framework based on several technologies to address the requirements of privacy, security and performance of the Internet of Things. The basis of the framework is the IOTA technology, a derivative of blockchains relying on a directed acyclic graph to create transactions instead of a linear chain. IOTA improves distributed ledger performance by increasing transaction throughput as more users join the network, making the network scalable. As IOTA is not designed for privacy protection, we complement it with privacy-preserving mechanisms: merge avoidance and decentralized mixing. Finally, privacy is reinforced by introducing usage control mechanisms for users to monitor the use and dissemination of their data. A Proof of Concept is proposed to demonstrate the feasibility of the proposed framework. Performance tests are conducted on this Proof of Concept, showing the framework can work on resource-constrained devices and within a reasonable time. The originality of this contribution is also to integrate an IOTA node within the usage control system, to support privacy as close as possible to the objects that need it.