上QQ阅读APP看书，第一时间看更新
The data layer
At the bottom layer of the stack is the data layer, which deals with the data structure and the physical storage of data in the blockchain.
The following diagram shows the common capabilities that are part of this layer:
The capabilities of the data layer, such as cryptographic protocols, hash functions, digital signatures, and others
The data layer includes capabilities that describe the transaction and data model, the type of participants that can connect and use the blockchain (that is, the permissions model), the structure of the chain and its blocks, and the cryptography and hash functions to secure data and generate digital signatures.