On April 8, the Bitcoin Core development team will demonstrate the “attack blocks” of the first cryptocurrency on the Signet testnet.

Specifically designed blockchain units require significantly more time for validation.
The main goal is to show the seriousness of four consensus vulnerabilities. They are intended to be addressed by the Great Consensus Cleanup with BIP-54.

This Bitcoin improvement proposal involves a batch soft fork to clean up the consensus of the first cryptocurrency network. One major update will fix several protocol weaknesses at once:
1)Fixing the “time distortion” attack. An old vulnerability that allows miners with high hash rates to manipulate block timestamps, artificially lowering mining difficulty. BIP-54 will fix the issue with new rules for the timestamps of the first and last block in each difficulty adjustment period.
2)Restricting the most computationally intensive transactions. Some specially crafted operations can take a very long time to verify—ranging from several minutes to an hour on weak hardware. This increases load on nodes and gives miners leverage over competitors. BIP-54 introduces a limit on the number of potentially executable signature operations in a single transaction. If there are too many, the transaction is considered invalid.
3)Eliminating the 64-byte transaction problem in the Merkle tree. An operation exactly 64 bytes in size creates ambiguity in the Merkle tree: it can be interpreted as either a leaf or an internal node. This weakens proof of inclusion for transfers and makes the Merkle root ambiguous. After activating BIP-54, transactions exactly 64 bytes long will become invalid.
4)Abandoning the need for the outdated BIP-30 check. This is an old safeguard against duplicate TxIDs. After activating BIP-34, this check is needed almost nowhere, but historically it has had to be kept in consensus. BIP-54 requires new Coinbase transactions to be different so that the old check can ultimately be removed.
Plan
Experts do not intend to demonstrate the worst-case attack scenario. They will hide script and transaction details to avoid providing additional information to malicious actors. Users will be shown blocks whose verification requires an order of magnitude more resources than usual.
The event will begin at 10:00 EST (14:00 UTC). Anyone can run a Bitcoin Core node on Signet ( which takes about 32-33 GB) and observe mining and block processing.