A public ledger is a tamperproof sequence of data that can be read and augmented by everyone.
Public ledgers have innumerable and compelling uses. They can secure, in plain sight, all kinds of transactions —such as titles, sales, and payments— in the exact order in which they occur.
Public ledgers not only curb corruption, but also enable very sophisticated applications —such as cryptocurrencies and smart contracts. They stand to revolutionize the way a democratic society operates. As currently implemented, however, they scale poorly and cannot achieve their potential.
Algorand is a truly democratic and efficient way to implement a public ledger. Unlike prior implementations based on proof of work, it requires a negligible amount of computation, and generates a transaction history that will not “fork” with overwhelmingly high probability.
Algorand is based on (a novel and super fast) message-passing Byzantine agreement.
For concreteness, we shall describe Algorand only as a money platform.