Blockchain Encryption Faces Quantum Threat as Post-Quantum Deadline Looms for 2030

The cryptographic foundations of major blockchains like Bitcoin and Ethereum — including elliptic curve signatures and SHA-256 hashing — are under growing scrutiny as quantum computing advances. Shor's algorithm, developed in 1997, could allow a sufficiently powerful quantum computer to break elliptic curve and RSA-based signature schemes in polynomial rather than exponential time. Researchers now estimate that quantum computers may compromise Bitcoin's signature scheme with fewer qubits than previously believed. In response, regulators in the US and EU are mandating that critical infrastructure transition to post-quantum cryptographic algorithms by 2030. While signature schemes and key exchange protocols are most at risk, hash functions like SHA-256 and symmetric encryption such as AES are considered relatively resilient, though Grover's algorithm does offer quantum computers some speedup against hash-based systems.