Key Takeaways
- Independent researcher Giancarlo Lelli successfully compromised a 15-bit elliptic curve encryption key through quantum computing, securing a 1 BTC reward from Project Eleven
- This represents the most significant documented quantum assault on elliptic curve cryptography in the public domain
- While Bitcoin (BTC) operates on 256-bit keys — substantially more complex than the compromised 15-bit system — the technological divide continues to shrink
- Approximately 6.9 million BTC stored in addresses with publicly visible keys may face vulnerability to advanced quantum computing attacks
- Security specialists remain split on timelines — projections range from several years to multiple decades before quantum technology becomes a genuine security concern
Giancarlo Lelli, working independently, has successfully compromised a 15-bit elliptic curve encryption key utilizing publicly available quantum computing resources. For this accomplishment, Project Eleven — a startup focused on post-quantum security solutions — awarded him a bounty of 1 BTC, valued at more than $78,000.
According to Project Eleven, this marks the most substantial quantum-based assault on elliptic curve cryptography documented in public records.
Lelli employed a modified version of Shor’s algorithm to extract a private key from its corresponding public counterpart within a computational space containing 32,767 potential values. Shor’s algorithm specifically exploits the mathematical foundations securing digital signatures across Bitcoin, Ethereum, and the majority of blockchain networks.
Prior to Lelli’s achievement, engineer Steve Tippeconnic successfully broke a 6-bit elliptic curve key in September 2025 utilizing IBM’s 133-qubit quantum processor. Lelli’s 15-bit breakthrough represents a 512-fold increase in complexity.
Bitcoin (BTC) relies on 256-bit elliptic curve cryptography for security. While a considerable distance separates this from the 15-bit key recently compromised, Project Eleven suggests the challenge is “progressively being recognized as an engineering obstacle rather than a barrier rooted in fundamental physics.”
“The computational resources needed for attacks of this nature continue declining, and the practical barriers to execution are falling alongside them,” explained Alex Pruden, CEO of Project Eleven.
Bitcoin Holdings Potentially Vulnerable to Quantum Attacks
Project Eleven calculates that approximately 6.9 million Bitcoin reside in wallet addresses where public keys remain exposed on the blockchain. These holdings could face significant risk should quantum computing capabilities advance sufficiently.
Bernstein analysts estimate roughly $450 billion worth of Bitcoin sits in legacy wallet addresses featuring publicly visible keys.
The danger remains theoretical at present. Existing quantum computing systems fall well short of the computational power required to compromise production-grade cryptographic systems.
Research from Google suggested that compromising 256-bit elliptic curve cryptography might demand fewer than 500,000 physical qubits. Subsequent analysis from the California Institute of Technology in collaboration with quantum startup Oratomic proposed the threshold could potentially be as minimal as 10,000 qubits.
Industry Response and Preparation Efforts
Bitcoin (BTC) development teams have introduced proposals for transitioning to quantum-resistant cryptographic systems. Ethereum, Tron, StarkWare, and Ripple have similarly announced preliminary strategies addressing this challenge.
At Paris Blockchain Week in April, Blockstream CEO Adam Back emphasized the importance of proactive preparation despite potentially distant timelines. “Quantum computing technology continues facing significant validation hurdles. Present systems essentially function as laboratory prototypes,” Back stated.
Bernstein analysts have recommended measured responses, characterizing quantum computing as representing a medium to long-range infrastructure evolution rather than an imminent crisis.
Within the Bitcoin (BTC) ecosystem, current consensus estimates place the necessary preparation timeline at three to five years, according to Bernstein’s assessment.
Project Eleven, supported by Castle Island Ventures, Coinbase Ventures, and Variant, secured $20 million through a Series A funding round this year, achieving a $120 million post-money valuation.
