Peter Todd (born 1985, Canada) is a cryptographer, applied cryptography consultant, and Bitcoin Core developer. He is known for his focus on Bitcoin protocol security, scalability, and his outspoken views on technical trade-offs.
BitcoinTalk and Satoshi: Todd registered on BitcoinTalk on December 7, 2010 under the username “retep” (Peter spelled backwards). Three days later, on December 10, he replied to a Satoshi Nakamoto post in the “Fees in BitDNS confusion” thread, where Satoshi had described a concept for transaction replacement — what would later become known as Replace-by-Fee. This was only Todd’s second post on the forum. Satoshi’s last public post came two days later, on December 12, 2010.
Bitcoin Core Contributions: Todd became an active Bitcoin Core contributor, focusing on protocol-level security, transaction policy, and network resilience. He was a vocal participant in technical debates about Bitcoin’s direction.
Replace-by-Fee (RBF): Todd is best known for championing Replace-by-Fee (RBF), which allows unconfirmed transactions to be replaced by new versions with higher fees. The concept was formalized in BIP 125, co-authored by David A. Harding and Peter Todd.
OpenTimestamps: Todd created OpenTimestamps, an open-source project that uses the Bitcoin blockchain to create tamper-proof timestamps, allowing anyone to prove that a document existed at a particular point in time.
HBO Documentary (October 2024): In October 2024, the HBO documentary “Money Electric: The Bitcoin Mystery” named Todd as a candidate for Satoshi Nakamoto’s true identity, pointing to his December 2010 reply to Satoshi’s post as evidence. Todd denied the claim, calling it irresponsible and dangerous.
2 entries
Satoshi Nakamoto describes a possible design for transaction replacement — allowing a double-spend with a higher fee to replace the original transaction. This concept would later become known as Replace-by-Fee (RBF). Peter Todd replied to this post approximately 1.5 hours later.
Defined a signaling mechanism for opt-in Replace-by-Fee (RBF), allowing unconfirmed transactions to be replaced by new versions with higher fees. RBF improved fee estimation and market efficiency but was controversial for its impact on zero-confirmation transaction security.