Briefing
This research addresses the foundational challenge of constructing one-shot signatures (OSS) in the standard model, a cryptographic primitive where a signing key can authorize only a single message before self-destructing. The breakthrough introduces the first provably secure standard-model OSS, relying on indistinguishability obfuscation and the Learning With Errors assumption, fundamentally shifting the landscape of digital authentication by enabling unforgeable, single-use authorizations without relying on idealized or flawed prior models. This new theory holds profound implications for future blockchain architectures and decentralized systems, promising novel mechanisms for quantum-resistant authentication, truly unclonable digital assets, and enhanced privacy in a post-quantum era.
Context
Prior to this research, the concept of one-shot signatures, while theoretically appealing for its ability to enforce single-use authorizations, faced significant practical and theoretical hurdles. Existing constructions were either confined to artificial oracle models, lacking real-world applicability, or contained fundamental flaws, as seen in the work by Amos et al. The prevailing theoretical limitation was the inability to achieve provably secure OSS within the “standard model” ∞ a framework that avoids unrealistic cryptographic assumptions ∞ leaving a critical gap in the development of robust, single-use digital authentication mechanisms essential for advanced decentralized applications.
Analysis
The paper’s core mechanism centers on constructing the first standard-model one-shot signature by ingeniously combining indistinguishability obfuscation (iO) with the Learning With Errors (LWE) assumption. This approach fundamentally differs from previous attempts by moving beyond idealized oracle models, providing provable security for the single-use property of the signature. The new primitive operates by leveraging “permutable pseudorandom permutations” (permutable PRPs), which serve as a conceptual bridge to translate proofs that previously relied on random permutations in oracle models into robust, obfuscation-based proofs within the standard model. This allows for a signing key to inherently self-destruct or become invalid after a single use, a property impossible to achieve classically without strong, unproven assumptions, thus enabling a truly unclonable digital signature.
Parameters
- Core Concept ∞ One-Shot Signatures (OSS)
- New Mechanism ∞ Standard-Model Construction
- Key Assumptions ∞ Indistinguishability Obfuscation (iO), Learning With Errors (LWE)
- Key Primitive ∞ Permutable Pseudorandom Permutations (permutable PRPs)
- Key Authors ∞ Omri Shmueli, Mark Zhandry
- Conference Recognition ∞ CRYPTO 2025 Best Paper Award
Outlook
This research opens critical new avenues for post-quantum cryptography and decentralized system design. In the next 3-5 years, this theory could unlock real-world applications such as truly decentralized, blockchain-less cryptocurrencies, robust one-time signature tokens for sensitive transactions, and signature schemes with provably unclonable secret keys. It lays the groundwork for developing advanced quantum money with classical communication and novel non-interactive certifiable min-entropy schemes, fostering a more secure and private digital economy resistant to future quantum threats and enabling entirely new paradigms for digital asset management and authentication.
