Bitcoin Core v30.0 Update Sparks Fierce Debate Over Data Limits

The recent Bitcoin Core v30.0 update has ignited a fierce debate within the Bitcoin community, primarily due to significant changes to the OP_RETURN function. This update, rolled out on October 11, expands the data limit for OP_RETURN outputs from 80 bytes to 100,000 bytes and permits multiple OP_RETURN outputs per transaction. Historically, OP_RETURN allowed attaching metadata like text or images to transactions without impacting their monetary function; this expansion now enables node operators to process much larger and more complex data structures, such as NFT-style inscriptions or application metadata, by default.

Proponents view this as a beneficial evolution, fostering “richer on-chain experimentation” and providing an “uncensorable, unmodifiable registry” for historical data, potentially giving Bitcoin parity with smart-contract platforms like Ethereum. Blockstream CEO Adam Back defends the update, citing legitimate security and robustness fixes from skilled developers.

However, critics, including prominent developer Luke Dashjr, have labeled v30.0 “malware,” asserting it “broke” datacarrier size control and facilitates “spam outputs.” Dashjr warns this could accelerate blockchain bloat and increase fee pressure, potentially pushing average block sizes from 1.5 MB to 4 MB. Data from Mempool Research indicates inscriptions and OP_RETURN transactions already constitute a substantial portion of Bitcoin’s transaction count and weight. Critics argue this dilutes Bitcoin’s primary role as a peer-to-peer financial network and could enable harmful content, leading Dashjr to advocate for a “mass migration to Knots,” an alternative client with stricter policies.

Amidst this rift, community members have proposed compromises. Cryptographer Nick Szabo suggested deprecating OP_RETURN for financial transactions while allowing pruning of newer data. BitMEX Research introduced OP_Return2, a soft-fork mechanism for committing to hashes of up to 8 MB of external data without requiring full nodes to store or validate it, aiming to preserve data integrity and reduce on-chain bloat. However, its adoption depends on miner incentives and existing lower-cost timestamping alternatives.

(Source: https://cryptoslate.com/new-bitcoin-software-labeled-malware-as-btc-developers-split-by-code-change/)