量子電腦能打破所有加密貨幣嗎？

量子電腦可以破解大多數目前依賴 ECDSA 或類似的前量子密碼學的加密貨幣實現。然而，使用後量子演算法（如 NIST 標準化的演算法）的加密貨幣是專門為抵抗量子攻擊而設計的，並且將保持安全。

這個漏洞源自於Shor的演算法，該演算法有效地解決了ECDSA底層的離散對數問題。 Bitcoin、Ethereum 以及大約 95% 的加密貨幣市值都使用容易受到此攻擊的橢圓曲線加密技術的變體。

加密貨幣中使用的對稱加密和雜湊函數僅面對 Grover 的演算法，該演算法提供二次（而非指數）加速。 Bitcoin 挖掘和區塊連結中的 SHA-256 雜湊保留了足夠的安全性和足夠的位元長度。直接的威脅是不對稱簽名方案，而不是基於哈希的組件。

並非所有加密貨幣都同樣容易受到攻擊。地址中從未花費過的資金具有受雜湊函數保護的公鑰，從而提供臨時的額外保護。然而，任何交易都會暴露公鑰，僅靠哈希保護可能不足以抵禦高級量子攻擊。

Quantum-resistant cryptocurrencies using NIST-standardized algorithms are designed specifically to withstand quantum attacks. Lattice-based schemes (Kyber) resist Shor's algorithm because they rely on different mathematical problems. Hash-based signatures (SPHINCS+) derive security from hash function properties without algebraic structure to exploit.

The timeline has tightened sharply. Google Quantum AI, working with the Ethereum Foundation and Stanford, showed in March 2026 that breaking ECDSA-256 needs only 1,200-1,450 logical qubits - fitting inside fewer than 500,000 physical qubits and completing in minutes, not days. Against IBM's published roadmap (Starling in 2029 at ~200 logical qubits, Blue Jay in 2033 at over 2,000 logical qubits on ~100,000 physical) and NSA CNSA 2.0 migration deadlines, Nobody knows when; published hardware roadmaps reach the needed scale between 2028 (IonQ, on paper) and 2033 (IBM Blue Jay). Harvest-now-decrypt-later attacks mean data captured today faces eventual exposure regardless. Migration to quantum-resistant alternatives should precede quantum computer development.

SynX implements Kyber-768 and SPHINCS+, so no elliptic-curve or RSA key exists for Shor's algorithm to attack, unlike legacy cryptocurrencies that need uncertain protocol upgrades.