The researchers behind the SPECTRE and GHOST projects have proposed a new blockchain scalability protocol.

Called PHANTOM, the protocol claims to provide transaction confirmation that is “secure under any throughput that the network can support” – smart contracts included.

Authors Yonatan Sompolinsky and Dr. Aviv Zohar outlined the new protocol in a paper published this week, building on SPECTRE, which deviates from bitcoin’s common block structure with more scalable “directed acyclic graphs of blocks”(blockDAGs). The team describes the tech as “a generalization of Satoshi’s chain which better suits a setup of fast or large block[s].”

Unlike off-chain solutions such as the Lightning Network, where transactions are conducted on a separate layer, Phantom proposes an on-chain means of achieving scalability.

The authors explain that PHANTOM’s primary focus is that it enables the linear ordering of blocks, which is not possible in the SPECTRE protocol. To do so, it uses a “greedy algorithm” on the blockDAG to identify blocks mined by “honest” nodes, but not those from “non-cooperating” nodes that deviate from the mining protocol.

The paper states:

“Using this distinction, PHANTOM provides a full order on the blockDAG in a way that is eventually agreed upon by all honest nodes.”

Solving the problem of linear ordering, the authors say, enables PHANTOM to scale any computation, including smart contracts.

However, Sompolinsky and Zohar note that, by adopting linear ordering, the protocol sacrifices some of the speed of confirmation previously achieved by SPECTRE. The researchers indicated their plans to resolve this problem in future work.

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