LibraryScaling2018Design paperCorpus record
RapidChain: Scaling Blockchain via Full Sharding
RapidChain. Mahdi Zamani, Mahnush Movahedi and Mariana Raykova.
RapidChain shards the ledger completely and uses a committee protocol that tolerates a smaller honest fraction inside a committee than a classical open network.
A reading of the public paper. Not a copy, not a benchmark, and not a claim about any later network.
Ask whether 'full sharding' includes storage of the state the user is trusting. If one archive node holds it all, the word full is doing too much work.
The five-minute read
The defect
Partial sharding still makes every node touch the parts that were not sharded. Full sharding is a claim that communication, storage and computation all split.
The proposal
RapidChain shards the ledger completely and uses a committee protocol that tolerates a smaller honest fraction inside a committee than a classical open network.
The honest-fraction claim is per committee, and it depends on how commit
Cross-shard routing is part of the protocol, not an afterthought.
The bound
The percentages in the paper are for its model.
One action, walked through
- Sample committees.
- Order transactions inside one committee.
- Route a cross-shard payment so both committees have to accept it.
- How large is a committee?
The argument, unpacked
What the paper is for
Ask whether 'full sharding' includes storage of the state the user is trusting. If one archive node holds it all, the word full is doing too much work.
What happened after
Later production shards rarely match this committee protocol. The question it poses is still the right one.
What has to be true
- The percentages in the paper are for its model.
- It is not a report on any 2026 network.
- Committee size is a security parameter. Shrinking it is not free.
What happened after the paper
Later production shards rarely match this committee protocol. The question it poses is still the right one.
What to check before you use the idea
- What is sharded: compute, storage, or only the mempool?
- How large is a committee?
- How does a cross-shard payment abort?
Terms
- Full sharding
- A split of computation, storage and communication, not only of block production.
- Committee
- The small set trusted to order one shard.
The problem the paper names
Partial sharding still makes every node touch the parts that were not sharded. Full sharding is a claim that communication, storage and computation all split.
What the design proposes
- The honest-fraction claim is per committee, and it depends on how committees are sampled.
- Cross-shard routing is part of the protocol, not an afterthought.
- A full shard that cannot be verified by an outsider is a smaller trusted ledger.
How the mechanism is specified
- Sample committees.
- Order transactions inside one committee.
- Route a cross-shard payment so both committees have to accept it.
What this page does not treat as proven
- The percentages in the paper are for its model.
- It is not a report on any 2026 network.
- Committee size is a security parameter. Shrinking it is not free.
Why a venture studio still reads it
Ask whether 'full sharding' includes storage of the state the user is trusting. If one archive node holds it all, the word full is doing too much work.
This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.
Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.