[BIP Proposal] Limit ScriptPubkey Size >= 520 Bytes Consensus.

In a recent discussion on the Bitcoin Development Mailing List, Andrew Poelstra, Director of Blockstream Research, addressed the complexities surrounding the validity of pre-signed transactions within the Bitcoin network. He highlighted a significant challenge: the potential for creating arbitrarily long chains of pre-signed transactions, which poses a risk to the network's integrity. To mitigate this issue, Poelstra proposed an innovative yet controversial solution: whitelisting all existing Unspent Transaction Outputs (UTXOs), including their descendants and any subsequent UTXOs generated from these transactions. This approach would effectively impose a limit on the size of new coinbase outputs and their child transactions, with the intention of curbing the unrestricted expansion of transaction chains.

However, Poelstra was candid about the drawbacks of his proposal, acknowledging the technical difficulties and the indefinite delay in deployment it would entail. Despite these challenges, he stressed the importance of considering such measures as a means to address the confiscation issue within the Bitcoin ecosystem, demonstrating a commitment to exploring all possible solutions, regardless of their complexity or the hurdles they present. For more insights into Poelstra's research and contributions to the field, interested individuals can visit his website at https://www.wpsoftware.net/andrew.