Network Architecture

DAG Mempool and Consensus

The DAG mempool is the stage where validators accept and order external messages without executing transactions.

  • Users submit external messages to nodes in the active validator set.

  • Validators publish these messages into the consensus protocol and periodically agree on a shared ordered queue.

  • Consensus remains secure as long as at least 2F+1 out of 3F+1 participants follow the protocol.

  • No transaction execution or state changes occur at this stage, significantly reducing network and computational overhead.

  • After agreement, the queue is deduplicated and passed to the collator.

This is the first phase of Tycho. It provides collators with a shared, Byzantine-fault-tolerant buffer of external messages.

Collator

The collator executes both external and internal messages, produces blocks, and updates the blockchain state. It requires:

  • the ordered external message queue from the DAG mempool;

  • the current blockchain state.

Because no network coordination is required, a collator can continuously produce blocks at full node capacity. Given the same inputs and deterministic execution, every node can locally derive identical blocks. As a result, finality only requires exchanging hashes and signatures, not full block data.

Blocks are produced in parallel for two linked chains:

  • Shard blocks, which contain transaction execution results.

  • Master blocks, which serve coordination and synchronization purposes. Finality is reached upon master block confirmation.

Verifier

The verifier checks that a master block hash is signed by validators controlling more than two-thirds of the total stake.

  • Nodes exchange only signatures on the master block hash.

  • Once signatures exceeding the two-thirds threshold are collected, the master block can be propagated to network clients such as light nodes.

  • Since the master block references the latest shard block, separate shard block verification is unnecessary.

Interoperability

Within the TetraChain ecosystem, Tycho-based networks use the same account and message primitives as TON. Although block-level execution and structure differ, this allows consistent handling of messages and accounts across TetraChain applications.

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