Tag: quantum-safe

  • Quantum Computing Threat to Bitcoin: How Close Are Hackers to Breaking BTC?

    Quantum Computing Threat to Bitcoin: How Close Are Hackers to Breaking BTC?

    Bitcoin cannot currently be hacked by available quantum computers, but sufficiently advanced quantum machines could eventually threaten some of the cryptography protecting BTC ownership. The risk is serious enough that researchers are already testing quantum-resistant ways to protect Bitcoin before such computers become practical.

    What Quantum Computers Could Attack

    Bitcoin ownership depends on digital signatures. A wallet uses a private key to authorize spending, while cryptographic mathematics allows the network to verify the signature without revealing that private key.

    The potential problem is Shor’s algorithm. According to StarkWare, a sufficiently capable quantum computer running Shor’s algorithm could work backward from certain exposed public keys and calculate the corresponding private key. An attacker could then create a valid signature and spend the BTC.

    This does not mean Bitcoin’s blockchain itself suddenly disappears. The primary concern is unauthorized spending from vulnerable addresses.

    Which Bitcoin Is Most Exposed?

    Risk varies according to address usage. Bitcoin addresses where the public key has never been revealed have additional protection, as the blockchain initially exposes only a hash of that key. Once coins are spent, however, the public key may become visible.

    Older address structures and reused addresses can therefore present greater long-term concerns. A quantum attacker would still require hardware capable of completing the calculation before the legitimate owner safely moves the funds. Today’s quantum computers are nowhere near that capability.

    A Quantum-Safe Bitcoin Transaction Is Already Live

    Researchers have nevertheless begun preparing. On August 26, StarkWare researcher Avihu Levy demonstrated what the company describes as the first quantum-safe Bitcoin transaction on mainnet. It was confirmed in Bitcoin block 964,199 without changing Bitcoin’s consensus rules or introducing a soft fork.

    The Quantum-Safe Bitcoin method protected a 10,000-satoshi output using a construction designed to remain secure against a working quantum adversary. However, the demonstration was experimental. The transaction was non-standard, required direct submission to MARA Pool, and reportedly cost roughly USD 150-200 when computation and transaction expenses were considered.

    Does This Make Bitcoin Quantum-Proof?

    No. StarkWare itself argues Bitcoin will ultimately need protocol-level changes to provide comprehensive quantum resistance. Existing exposed public keys remain a separate challenge. Bitcoin developers would also need wallets, exchanges and users to migrate before a cryptographically relevant quantum computer becomes available.

    Final Thoughts

    Quantum computing is not an immediate Bitcoin security emergency, but waiting until an attack becomes practical would be dangerous. The recent mainnet experiment shows that researchers can already test defensive mechanisms on Bitcoin itself.

    For BTC holders, the key issue is therefore preparation: developing standards, upgrading wallet infrastructure and eventually migrating vulnerable funds before quantum hardware becomes powerful enough to threaten existing signature systems.

    FAQs

    1. Can quantum computers hack Bitcoin today? No. Current quantum computers are not powerful enough to break Bitcoin’s cryptography. The threat is considered a long-term risk rather than an immediate security emergency.
    2. How could quantum computers threaten Bitcoin? A sufficiently powerful quantum computer using Shor’s algorithm could potentially derive a private key from certain exposed public keys. That could allow an attacker to authorize unauthorized BTC transactions.
    3. Which Bitcoin addresses are most vulnerable to quantum attacks? Older or reused addresses with exposed public keys could face greater long-term risk. Addresses whose public keys have not yet been revealed have an additional layer of protection.
    4. What was StarkWare’s quantum-safe Bitcoin transaction? StarkWare researcher Avihu Levy demonstrated a quantum-resistant Bitcoin transaction on mainnet in block 964,199. The experiment protected a 10,000-satoshi output without requiring a Bitcoin soft fork.
    5. Does the quantum-safe transaction make Bitcoin quantum-proof? No. The demonstration was experimental and does not protect the entire Bitcoin network. Broader quantum resistance would likely require protocol upgrades, wallet changes and migration of vulnerable funds.
  • Sui’s Quantum-Safe Upgrade Preserves Existing Wallet Addresses With Post-Quantum Signatures

    Sui’s Quantum-Safe Upgrade Preserves Existing Wallet Addresses With Post-Quantum Signatures

    Sui is rolling out quantum-safe account security that lets users keep their current blockchain addresses while upgrading to post-quantum cryptography. The network will support ML-DSA-65 for standard accounts and SLH-DSA-SHA2-128s for high-value Move-based vaults, both designed to resist attacks from future quantum computers.

    Address Aliases Enable Seamless Migration

    Normally, switching cryptographic schemes requires creating a new address and moving all assets—a disruptive process for tokens, NFTs, identities, and smart contracts. Sui’s Address Aliases system avoids that entirely. An account can authorize a new post-quantum signer while the original blockchain address remains the transaction sender. Once native ML-DSA support is live, users simply authorize the new signer and later make it the sole authorized signer.

    Users can also derive an ML-DSA-65 key from their existing recovery phrase via a fresh derivation path, eliminating the need for a separate backup. Sui cautions that wallet software must clearly communicate the authority granted when adding an alias.

    Two Cryptographic Systems for Different Needs

    Sui splits quantum protection across two NIST‑standardized schemes:

    • ML-DSA-65 (FIPS 204, NIST Category 3) – a lattice‑based signature chosen for frequent transactions because it balances a strong security margin with practical verification speed.
    • SLH-DSA-SHA2-128s (FIPS 205, Category 1) – a hash‑based system reserved for high‑value vaults, providing a different mathematical foundation so that a weakness in lattice‑based crypto does not compromise all assets.

    This dual approach lets developers replace the vault authentication scheme via smart‑contract upgrades if future cryptanalysis reveals flaws in one family.

    Larger Signatures Shape Deployment Timeline

    Post‑quantum signatures are bulkier than Ed25519: ML-DSA-65 signatures are 3,309 bytes (public key: 1,952 bytes), while SLH-DSA‑SHA2‑128s signatures reach 7,856 bytes. Despite the size increase, Sui notes that ML-DSA verification performance is close enough to Ed25519 that per‑signature network costs need not rise.

    The rollout is staged:

    • Quantum‑safe vaults on Mainnet before end of 2026.
    • Native ML-DSA-65 accounts on Testnet by late 2026 and Mainnet in Q1 2027.
    • Wallet, SDK, and CLI support alongside independent audits and Testnet feedback.

    No immediate action is required from existing users. The migration is additive and optional, with clear warnings about potential scams that ask users to move all assets to a new address.

    Conclusion

    Sui’s quantum‑safe upgrade uses ML-DSA-65 accounts and SLH-DSA vaults while preserving existing addresses via Address Aliases. Users need do nothing now; audits, testing, and phased deployment continue.