Foundations of Blockchain

Proof of Existence library

A Proof of Existence library is a collection of methods that perform high-level tasks on a blockchain. The library contains all the operations that can be performed on a document submitted by a user. There are two main ways of performing operations on the user document, according to the design of the architecture: publish and verify.

The publish operation publishes the document digest, along with any other information passed by the user. Since we are using MultiChain streams for publishing, the data has to be formatted in a hexadecimal string, as mentioned earlier.

The following Document class shows the publish and verify methods, along with some methods that can be used to fetch the stream items:

class Document(object): ...