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Securely Scaling Permissionless Blockchains

Philipp Jovanovic, Omniledger and Swiss Federal Institute of Technology Lausanne (EPFL)


Anyone who has waited too long for a Bitcoin transaction to confirm or struggled over higher than expected fees should be aware of the problem.  Scalability — increasing the number of transactions and users without compromising decentralization and security — is a holy grail for permissionless blockchains.  It is extremely difficult to design a secure, permissionless, fully distributed ledger that performs as well as centralized payment processors like Visa.

From Bitcoin to Litecoin and from Dash to Ethereum, the best-known decentralized networks in the sector grapple with some version of this scalability puzzle.  It is considered one of the biggest remaining obstacles to the widespread use of cryptocurrencies around the world.

For Bitcoin Wednesday on 6 December 2017, Philipp Jovanovich, an authority on the subject of blockchain scalability, will present OmniLedger, the first scale-out distributed ledger that can preserve long-term security under permissionless operation.  His OmniLedger working prototype demonstrates throughput that scales linearly in the number of available validators.  It can therefore support workloads comparable to Visa while confirming typical transactions in less than two seconds.

Philipp is a cryptographer and post-doctoral researcher at the Swiss Federal Institute of Technology Lausanne (EPFL).  His research covers applied cryptography, information security, and decentralized systems.  He is a member of the Initiative for CryptoCurrencies and Contracts (IC3) and a scientific advisor to the DFINITY project.

He writes, “OmniLedger ensures strong correctness and security with a bias-resistant public randomness protocol that choose large statistically representative shards to process transactions.  It also introduces an efficient cross-shard commit protocol to handle transactions affecting multiple shards atomically.

In addition, it optimizes performance via scalable intra-shard parallel transaction processing, ledger pruning via collectively-signed state blocks, and optional low-latency trust-but-verify validation of low-value transactions.”


Philipp Jovanovic, Omniledger and Swiss Federal Institute of Technology Lausanne (EPFL)