Quantum computers issue a "realistic warning" to Bitcoin's encryption system... Emerging as a security competitive factor

Quantum computers may pose a threat to Bitcoin(BTC) security, sparking renewed attention. As successful cases of cracking elliptic curve encryption(ECC) based on publicly available quantum hardware with small keys emerge, debates about the future of “Bitcoin cryptography” have become more intense.

However, this achievement does not mean that Bitcoin network cryptography has been immediately broken. The experiment was limited to very small keys(15 bits), which are vastly less secure than Bitcoin’s actual security level(256 bits), so the market should interpret the message as not “imminent collapse,” but rather “accelerating trend.”

Successful cracking of “15-bit” keys… using publicly available quantum devices in just 45 minutes

This record comes from the “Q-Day Award” operated by Project Eleven. Independent researcher Giancarlo Lelli used a variant of Shor’s algorithm(Shor’s algorithm) to crack a 15-bit elliptic curve encryption key, derive the private key from the public key, and earn a 1 Bitcoin(BTC) reward.

Notably, the “device” part is worth attention. It was not a government-grade private system, but a publicly accessible quantum device with about 70 qubits(qubits), and the entire attack was completed within 45 minutes. Considering that the previous public record was for a 6-qubit system in September 2025, this indicates a 512-fold increase in complexity over seven months.

Bitcoin(BTC) uses 256 bits… but exposed addresses become variables

Bitcoin(BTC) employs elliptic curve encryption of the same series, but its actual security operates at the 256-bit level. The core point is that this 15-bit experiment does not mean immediate access to Bitcoin wallets; it requires computational resources “not in the same dimension” as current technology.

Nevertheless, the reason for heightened risk discussion is Bitcoin’s security model characteristics. Project Eleven estimates that among on-chain exposed public keys, about 6.9M BTC (roughly $520B, calculated at 1 USD = 1475 KRW, approximately 767 trillion KRW) are stored. This includes approximately 1.1 million BTC allegedly held by Satoshi Nakamoto(Satoshi Nakamoto), raising concerns: as technological progress accelerates, the “potentially vulnerable holdings” timetable may be moved forward.

“Collect now, decrypt later” scenario… defense evolving into an upgrade race

Alex Pruden, CEO of Project Eleven, stated: “The resource requirements for such attacks are continuously decreasing, and the actual threshold for execution is also lowering.” Recently, scenarios of “harvest now, decrypt later” have been frequently mentioned, where attackers pre-collect public keys and wait for future quantum performance improvements.

Theoretical resource estimates for attacks at the 256-bit level are also rapidly decreasing. Google’s white paper from April 2026 suggests fewer than 500k “physical qubits” may be needed, while research from Caltech and Oratomic indicates that, under neutral-atom(neutral-atom) methods, the required number of qubits can be reduced to 10k. Ultimately, the core of Bitcoin(BTC) security is not “whether it is immediately cracked,” but whether the network and wallet security can keep pace with quantum computer advancements, and how quickly they can respond in an “upgrade race.”

Article summary by TokenPost.ai

🔎 Market interpretation - Demonstration of cracking “15-bit ECC keys” using publicly available quantum hardware shifts market focus from “possibility” to “progress speed” - While this does not mean Bitcoin(256-bit) will collapse immediately, it serves as a warning signal that “costs/thresholds may fall faster than expected” - The existence of on-chain exposed addresses(estimated 7.67M BTC) reinforces the “technological development → increased vulnerabilities” logic 💡 Strategy points - Common to individuals and institutions: the core is “adapting to the speed of quantum progress,” not “being immediately hacked” (upgrade race) - Wallet/operation security: minimize public key exposure (avoid address reuse, transfer to new addresses when necessary), reduce “attack surface of exposure” - Risk assessment scenarios: develop security roadmaps for long-term holdings based on the possibility of “harvest now, decrypt later,” including transfer/distribution/strategy - Network perspective: as discussions on quantum-resistant cryptography(PQC) expand, standard adoption/upgrade schedules (consensus, compatibility, testing periods) may influence price volatility 📘 Terminology clarification - Elliptic Curve Cryptography(ECC): public key encryption used for Bitcoin signatures, with private key signing and public key verification - Shor’s algorithm(Shor’s algorithm): quantum algorithm capable of quickly solving large integer factorization/discrete logarithm problems, posing potential threats to ECC, RSA, etc. - Qubit(Qubit): quantum computer’s information unit (different from classical bits, utilizing superposition/entanglement) - Physical qubit(Physical qubit): actual quantum bits that contain errors (more are needed with error correction to realize “logical qubits”) - ‘Harvest now, decrypt later’: even if currently difficult to crack, data is stored first, and future, more powerful quantum computing is used to decrypt it

💡 FAQ(

Q. Does this “15-bit ECC key cracking” mean Bitcoin wallets can be immediately cracked? No. This experiment demonstrated a very small 15-bit key, while Bitcoin’s actual security level is 256 bits. However, the fact that “public quantum devices actually attacked ECC” is interpreted as a long-term signal to be cautious about the development speed of quantum computers. Q. Which Bitcoins are more at risk? The variable emphasized in the article is “public key exposure.” There are concerns that assets stored in addresses with exposed on-chain public keys (estimated 500k BTC) could become more vulnerable. Not all wallets are immediately at risk, but as address reuse and other behaviors increase public key exposure, attackers’ opportunities also expand. Q. What should ordinary users prepare now? The core is “preparation,” not “immediate panic.” It is recommended to avoid address reuse (use new addresses) and review security strategies for long-term holdings. In the medium to long term, the network/wallet ecosystem may discuss anti-quantum cryptography)PQC( upgrades, so checking security update notices and implementation plans from major wallets and exchanges is a practical step.

TP AI note: Uses language models based on TokenPost.ai for article summaries. May omit key content or differ from facts.