Bitcoin marked the beginning of a new era in digital finance; the data structure known as the blockchain enabled financial transactions to be executed in a secure decentralized manner, therefore revolutionizing the financial landscape. Blockchains naturally form environments where the participants act for profit (i.e., participants are rational). Nevertheless, current works typically analyze the security of blockchain protocols in the traditional setting where some of the participants are malicious and the rest are honest as there is no general framework to analyze blockchains from a rational perspective. Furthermore, blockchain systems are complex and consist of several components that handle different performance aspects, such as the network layer or Layer 0, the consensus layer or Layer 1, and the off-chain network or Layer 2. All these layers interact with each other and the security of each layer depends on the security of its substrate layer and vice versa. Therefore, the composition of protocols in the blockchain setting is vital for the security guarantees and the correct operation of cryptocurrencies. The goal of this project is to introduce a composable framework for the security analysis of blockchain protocols under a hybrid model of both rational and malicious participants. This is a significant yet currently missing tool with impact across multiple disciplines such as computer science and economics.