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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.
Algorand removes the technical barriers
that for years undermined mainstream blockchain adoption: decentralization, scale, and security. Now you can build on a stable platform you trust.
Algorand is the first blockchain to provide immediate transaction finality
Our consensus mechanism is permissionless and PURE PROOF OF STAKE™. It ensures full participation, protection, and speed within a truly decentralized network. With blocks finalized in seconds, Algorand’s transaction throughput is on par with large payment and financial networks. And Algorand is the first blockchain to provide immediate transaction finality. No forking. No uncertainty.
The era of a decentralized, borderless economy is here. Algorand is the foundation.
Algorand uses cryptographic sortition to select users to propose blocks for a given round. When a block is proposed to the blockchain, a committee of voters is selected to vote on the block proposal. If a super majority of the votes are from honest participants, the block can be certified.
Consenus level security
Algorand’s decentralized Byzantine agreement protocol can tolerate an arbitrary number of malicious users as long as honest users hold a super majority of the total stake in the system. Two important features of the consensus protocol prevent powerful adversaries from corrupting enough users so as to control block generation:
First, the adversary does not know which users he should corrupt. In fact the users who are called to certify a new block are secretly and individually selected. Second, when the adversary realizes which users are selected, it is too late for him to benefit from attacking them. Those users has already fulfilled their responsibility in the consensus protocol. In the next round of block certification, a new set of users will again be privately and individually chosen.
Rewards
In Algorand, the power is in the hands of the users holding stake. Every user receives an amount of rewards proportional to their stake for every block that is committed to the chain. We do so to encourage users to join the Algorand platform and accelerate our path to decentralization.
Protocol evolution
Proposed changes are posted on the blockchain The community uses Algorand’s consensus protocol to vote to accept or reject the change When accepted, the community agrees on the block where the change happens Everyone switches to the new protocol at the same time Algorand is rooted in the idea that the system should allow for changes and avoid inflexible policies—enabling both the community and the protocol to evolve. The Algorand platform takes a consensus approach to protocol changes, which facilitates continuous evolution of the protocol and eliminates potential hard forks that could fracture the community. This ability is powered by the Algorand consensus protocol that enables the users to reach consensus on anything. Not just on the next block, but also on a protocol upgrade.
Jing Chen, Silvio Micali
