Blockstream Researcher Proposes Quantum-Resistant Bitcoin Signature Scheme

A Blockstream researcher, Jonas Nick, has proposed a new quantum-resistant signature scheme designed for Bitcoin. The proposal aims to support secure multi-device signing while keeping signature sizes smaller than current post-quantum standards.

SHRIMPS Introduces Multi-Device Quantum Signatures

In a recent tweet post, Jonas Nick introduced SHRIMPS, describing it as a hash-based construction. It allows multiple devices loaded from the same seed to independently generate signatures of around 2.5 KB.

This is roughly three times smaller than the current post-quantum standard SLH-DSA, which produces signatures of approximately 7.8 KB. However, the smaller size improves efficiency while maintaining quantum-resistant security.

“Please welcome SHRIMPS to the family of stateful PQ signatures.” “SHRINCS gave ~324-byte sigs but is single-device. SHRIMPS addresses multi-device.”

SHRIMPS Solves Multi-Device Wallet Limitations

Earlier work in this space, including SHRINCS, produced impressively small signatures but was limited to a single device. Moving a seed to a new device or running it across backup hardware meant falling back to much larger stateless signatures, undermining the efficiency gains.

SHRIMPS removes that constraint with a few key design principles:

• Any device loaded from the same seed can produce compact signatures independently
• The total number of devices is capped at a preset limit, typically 1,024
• If a device loses its state and reloads, it returns to the compact path automatically
• Security degrades gradually rather than collapsing if the device limit is exceeded

Why Now: The Google Factor

The proposal comes as quantum computing risks gain attention. Google researchers recently suggested that breaking elliptic curve cryptography may require fewer resources than previously estimated.

Google’s researchers showed that ECDLP-256, the standard securing most blockchain networks, could theoretically be cracked using fewer than 1,200 logical qubits, representing a roughly 20-fold reduction in hardware requirements from earlier estimates.

Researcher Justin Drake called it a “monumental day” and estimated at least a 10% probability that a quantum computer could recover a Bitcoin private key by 2032.

Why It Matters for Bitcoin

Bitcoin keys are typically used for only a small number of signatures, and multi-device wallet setups are common. SHRIMPS is designed with both realities in mind. Important points include:

• Bitcoin’s current elliptic curve cryptography is not broken today
• The threat lies in signature security, not mining
• Post-quantum upgrades require network-wide coordination and take years to implement
• Every wallet would need to upgrade, including wallets nobody controls, like Satoshi’s

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