Various implementations disclosed herein enable blockchain programming in NB-IoT devices. In various implementations, a method of blockchain authentication is performed by a computing device including one or more processors, and a non-transitory memory. In various implementations, the method includes maintaining a blockchain for a machine-to-machine network, wherein the machine-to-machine network is a narrowband internet of things network. In some implementations, the method includes receiving a request for a first set of data from the blockchain by a second device. In some implementations, the method includes determining based on the request, the first set of data from the blockchain by traversing a series of blocks from the blockchain. In some implementations, the method includes packaging the first set of data from the blockchain according to a protocol into a packaged data unit and transmitting the packaged data unit to the second device.