IOStoken - The Next-Generation,Secured, Highly Scalable Ecosystem for Services

EFFICIENT DISTRIBUTED SHARDING

an innovative sharding scheme that makes shards sufficiently large and strongly bias-resistant via a combination of a client-server randomness scavenging mechanism and leader election via cryptographic sortition.

Proof-of-Believability

A groundbreaking Byzantine consensus protocol with a Believable-First approach that guarantees safety and liveness of the system while largely maximizes the transaction throughput by size-one-shard.

Proof of Believability has a few advantages over Proof of Work. It enables high transaction speed without compromising network security. In order to achieve this, it uses several factors including how many IOST tokens the node holds, its reputation, its contribution, and its behavior.

Proof of Believability requires significantly less computational power than Proof of Work. It also tackles the scalability problem head-on. PoB uses elements such as microstate blocks and a dynamic sharding protocol to reduce storage, processing power, and cost to keep transaction throughput high and secure.

PoB eliminates the need for an energy-hungry Proof of Work protocol, which stands as a barrier to blockchain becoming widely adopted. With the PoB system, a node is validated based on its past contributions and behaviors.

Servi

A major challenge faced by traditional Proof-of-Stake consensus mechanism is the tendency towards centralization. In order to mitigate this risk, we introduce Servi as both a measurement of users’ contribution to the community and a way to encourage members to contribute to the continued development of the IOSChain. It has the following attributes:

Non-tradable: Since Servi is not designed as a medium of exchange, Servi can not be traded or exchanged in any way. Self-destructive: After validating a block, the system will automatically clear the Servi balance owned by the validator. In this way, nodes with high believability scores can take turns in validating blocks, to ensure a fair block generation process. Self-issuance: Servi will be generated and deposited to user accounts automatically after certain contributions, such as providing community services, evaluating services provided by another entities, and/or making other special contributions.

TOKENS AND MOTIVATIONS

In the IOS system, IOS Token, like tokens in other blockchain systems, serves as the medium of exchange for all transactions and commission fees. More importantly, IOS also plays a important role in calculating a user’s believability score. All IOS tokens will be generated in the Genesis Block. In the IOS ecosystem, IOS tokens can be used for:

• Payment: Payments for services and goods provided by merchants or other community members.
• Commission: Payment to validators as compensation for running smart contracts, processing messages and transactions, and using resources shared by the general ecosystem including but not limited to storage space, computing power, etc. The commission fee incentivizes the validators and prevents malicious users from damaging the interests of the community through excessive deployment of smart contracts.
• Believability: IOS tokens will be used to calculate users’ believability scores (will be explained in the following section).

INTER-SHARD TRANSACTIONS

The mechanism that supports inter-shard transactions is critical in the system, since transactions are likely to happen cross shards. We introduce a Byzantine Shard Atomic Commit (Atomix) protocol to ensures the atomicity cross shards. This protocol prevents double spending and keeps the consistency of transactions. Our design is a variant of the Omniledger algorithm.