Conflux vs IOTA: Understanding the DAG Blockchain Debate

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Conflux, a next-generation public blockchain built on Directed Acyclic Graph (DAG) technology, has been making waves in the blockchain community—not through hype, but through rigorous academic research and technical innovation. Backed by a team of elite computer scientists from Tsinghua University’s Yao Class and led by Turing Award winner Professor Andrew Yao, Conflux aims to solve one of blockchain’s most persistent challenges: scalability without compromising security or decentralization.

Unlike many projects that promise "million TPS" or "infinite scalability," Conflux takes a grounded, research-driven approach. In this deep dive, we’ll explore how Conflux leverages DAG to overcome the limitations of Nakamoto consensus, compare it with other DAG-based systems like IOTA, and explain why its design offers a more secure and scalable future for decentralized networks.

The Scalability Problem in Traditional Blockchains

At the heart of blockchain inefficiency lies the Nakamoto consensus—the mechanism used by Bitcoin and Ethereum. While secure, it suffers from low throughput due to its reliance on a linear chain structure.

In Bitcoin, blocks are added sequentially. To maintain security, the network keeps block production slow (e.g., one block every 10 minutes) and block sizes small. This minimizes network propagation delays and reduces the chance of forks—temporary splits in the chain caused when two miners produce blocks simultaneously.

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However, this conservative approach severely limits transaction throughput (TPS). Increasing block size or frequency would cause more frequent forks, leading to wasted computational resources and reduced security—because the effective length of the honest chain shortens, making it easier for attackers with less than 50% hash power to launch successful attacks.

This is the scalability-security trade-off: you can’t scale up without weakening security.

How Conflux Uses DAG to Break the Trade-Off

Conflux introduces a novel solution: replacing the linear blockchain with a Directed Acyclic Graph (DAG) structure. Instead of forcing blocks into a single chain, Conflux allows multiple blocks to be generated concurrently and organizes them into a tree-like DAG using two types of links:

This design enables high-speed block production without creating destructive forks. All blocks—whether on the main chain or side branches—are preserved and contribute to consensus.

The Role of the Pivot Chain

To achieve consensus on transaction order, Conflux selects a pivot chain (also called the “main chain”) using the GHOST rule (Greedy Heaviest Observed Subtree). Starting from the genesis block, each subsequent block in the pivot chain is chosen based on which child has the largest subtree—including all referenced blocks.

Because even off-chain blocks influence pivot chain selection, attackers cannot ignore them. This ensures that as long as honest nodes control over 50% of hash power, they will always dominate the heaviest subtree, securing the network.

Transaction Ordering and Finality

Once the pivot chain is established, Conflux defines a total order for all blocks and transactions:

  1. Epoch-based ordering: Each block on the pivot chain defines an epoch. Off-chain blocks belong to the epoch of the first pivot block that references them.
  2. Topological sorting within epochs: Blocks are ordered based on their dependencies.
  3. Conflict resolution: Transactions are processed in global order. If two transactions conflict (e.g., double-spend), only the first one is valid.

This deterministic process ensures all nodes reach consensus on the final state—even in a highly parallel environment.

Security Against Double-Spending Attacks

A common concern in any blockchain is double-spending. In Conflux, reversing a transaction requires altering its position in the global order—something extremely difficult due to the pivot chain’s security model.

An attacker would need to:

Given that subtree weight grows exponentially with honest mining, the probability of success drops rapidly over time. Users can calculate confirmation based on acceptable risk and hash rate assumptions—offering quantifiable finality, not just probabilistic assurance.

Performance: Real-World Results

Conflux tested its prototype on Amazon EC2 with 10,000 nodes under realistic network conditions (20 Mbps bandwidth per node). Results showed:

These benchmarks demonstrate that Conflux achieves high throughput while maintaining decentralization and security—without relying on permissioned validators or complex stake mechanisms.

Conflux vs Other DAG Projects

While several projects use DAG structures, their designs vary significantly in security, decentralization, and functionality.

IOTA: Vision vs Reality

IOTA uses a DAG called Tangle, aiming for feeless microtransactions in IoT environments. Its vision is compelling—but its implementation faces serious issues:

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Byteball: Centralized Consensus

Byteball improves on IOTA by introducing a total order via "witnesses"—trusted entities that sign and finalize transactions. However, this introduces centralization risks, similar to EOS-style DPoS systems.

Conflux avoids this by using PoW + GHOST, ensuring full decentralization and censorship resistance.

Nano & Moledao: Block-Lattice Models

Nano and Moledao use a block-lattice architecture where each user has their own chain. While efficient for payments, their consensus relies on voting mechanisms (Delegated Proof-of-Stake), which are vulnerable to long-range attacks and require trusted validators.

In contrast, Conflux maintains Nakamoto-style security with PoW while achieving high throughput via DAG.

Use Cases and Development Roadmap

Conflux is exploring several high-impact applications:

The core team consists of around 20 researchers and engineers based in Beijing, with plans to expand development sites nationwide to grow the ecosystem.

Mainnet launched successfully in Q3 2019 (as planned), and ongoing upgrades continue to enhance performance and developer tooling.

Regulatory Compliance and Industry Standards

Conflux supports regulatory clarity and has proactively initiated compliance procedures, including registration under China’s Blockchain Information Service Regulations. While services were not yet public at the time of initial reporting, compliance remains a priority as the platform scales.

Frequently Asked Questions (FAQ)

Q: Can Conflux prevent spam or garbage transactions?
A: Yes. While currently relying on basic PoW for spam deterrence, Conflux is actively researching advanced incentive models to strengthen economic security against denial-of-service attacks.

Q: What is Conflux’s transaction finality time?
A: Confirmation takes about 10 minutes, comparable to Bitcoin but with much higher throughput. Finality is probabilistic but quantifiable based on hash rate assumptions.

Q: Is Conflux compatible with Ethereum?
A: Conflux supports EVM compatibility, enabling easy migration of dApps and tools from the Ethereum ecosystem.

Q: How does Conflux differ from Algorand or other high-performance chains?
A: Unlike Algorand’s pure PoS model requiring coordination among validators, Conflux uses PoW for greater decentralization and resilience against adaptive attacks.

Q: Does Conflux have a token?
A: Yes. The native token ($CFX) powers transactions, staking, and governance on the network.

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Q: Can Conflux run smart contracts?
A: Absolutely. Thanks to its total transaction ordering, Conflux supports full Turing-complete smart contracts—something IOTA and early DAG systems cannot offer.

Core Keywords

Conflux represents a significant leap forward in blockchain architecture—one that combines academic rigor with practical engineering. By rethinking how blocks are ordered and validated, it offers a scalable, secure, and truly decentralized alternative to both traditional chains and flawed DAG implementations like IOTA.