Near One chief technology officer Anton Astafiev warned that quantum attacks could create a proof-of-ownership crisis, not only a cryptographic one. His concern is that once quantum machines can derive private keys, blockchains may no longer have a reliable and privacy-preserving way to determine who legitimately controls on-chain assets.
The warning reframes post-quantum security as more than a key-upgrade problem. The deeper risk is that private-key possession may stop being enough to prove lawful ownership when legacy cryptography becomes vulnerable.
NEAR Pushes Quantum-Safe Ownership Tools
NEAR Protocol has already published a set of protocol and ecosystem measures aimed at preserving verifiable ownership. Its approach includes integrating FIPS-204, also known as ML-DSA or Dilithium, as a lattice-based post-quantum signing option, with engineering work targeting testnet deployment by the end of Q2 2026.
The network’s account model gives it another migration advantage. Because NEAR accounts are decoupled from a single fixed keypair, rotatable access keys allow users to move toward quantum-safe credentials with a single transaction while preserving account identity.
Near One is also researching zero-knowledge proofs that would let users prove knowledge of an original seed phrase without revealing it. That matters because ownership could be anchored in seed knowledge rather than exposed private keys, since the hashing path from seed to private key is not vulnerable in the same way as signature schemes.
The ecosystem work extends beyond core protocol changes. NEAR is engaging software and hardware wallet vendors and developing quantum-safe cross-chain signatures for its Chain Signatures MPC network, reflecting a broader effort to protect ownership across multiple chains rather than only inside NEAR’s own environment.
Bitcoin Faces a Harder Migration Path
Bitcoin’s challenge is more structural. Its security model relies on elliptic curve cryptography, which is vulnerable to Shor-style quantum attacks once sufficiently powerful hardware exists, and the uncertainty around timelines complicates coordinated action across a conservative decentralized network.
A March 2026 research note cited in the industry suggested that future quantum machines could break ECC quickly, though estimates still range from a few years to decades. That divergence leaves holders and infrastructure providers with a planning problem where waiting too long could create systemic exposure.
The risk is especially acute for coins whose public keys are already visible on-chain. Roughly 6.9 million BTC, including an estimated 1.1 million BTC tied to early addresses, sit in wallets where public-key exposure could make balances directly vulnerable once quantum key recovery becomes practical.
Taproot adds another dimension to the debate. While it improves privacy and efficiency, public keys become exposed when outputs are spent, meaning the moment of transaction can expand the attack surface compared with address types that keep public keys hidden until use.
Bitcoin’s governance culture makes a fast network-wide migration difficult. Its decentralized upgrade process and conservative security posture mean off-chain or hybrid ownership proofs may become necessary before a full cryptographic transition can be broadly adopted.
One such proposal is PACTs, or Proof of Address Control with Timestamp, introduced in May 2026. The model uses a silent BIP-322 commitment, OpenTimestamps anchoring and future STARK-based redemption through a soft fork to help dormant holders prove pre-quantum control without moving funds on-chain.
Paradigm’s paper frames PACTs as a way to protect an estimated $75 billion to $84 billion of dormant bitcoin. The proposal matters because dormant balances need a path to prove ownership before quantum risk becomes executable, especially when moving funds could itself expose vulnerable public keys.
Astafiev’s warning captures the operational dilemma facing protocols, exchanges and custodians. If private keys can be derived by attackers, the industry will need ownership proofs that survive beyond signature validity and can distinguish legitimate control from quantum-enabled theft.
Near-term milestones will shape how quickly that transition becomes practical. NEAR’s testnet work through the end of Q2 2026 should reveal prover and verifier costs, while Bitcoin proposals such as PACTs still require tooling, coordination and potential soft-fork infrastructure.
Until quantum-resistant proof mechanisms become widely deployed, custodians and holders of dormant addresses face a growing governance, liquidity and migration risk. The next phase of post-quantum readiness will be about proving rightful control, not merely swapping one signature scheme for another.
