Synchronized DNA Sources for Unconditionally Secure Cryptography

Secure communication is the cornerstone of modern infrastructures, yet achieving unconditional security -resistant to any computational attack- remains a fundamental challenge. The One-Time Pad OTP, proven by Shannon to offer perfect secrecy, requires a shared random key as long as the message,...

Eve'S Forgery Probability from Her False Acceptance Probability: Interactive Authentication, Holevo Information and the Min-Entropy

We obtain estimates for Eve's forgery probability, namely the probability that she is able to forge a message which Alice or Bob mistakenly accept over a noisy Quantum channel for generating a shared Quantum secret key. This probability is related to Eve's success probability obtained in a previo...

On-Chip Semi-Device-Independent Quantum Random Number Generator Exploiting Contextuality

We present a semi-device-independent quantum random number generator QRNG based on the violation of a contextuality inequality, implemented by the integration of two silicon photonic chips. Our system combines a heralded single-photon source with a reconfigurable interferometric mesh to implement...

Finite-Size Security of QKD: Comparison of Three Proof Techniques

We compare three proof techniques for composable finite-size security of quantum key distribution under collective attacks, with emphasis on how the resulting secret-key rates behave at practically relevant block lengths. As a benchmark, we consider the BB84 protocol and evaluate finite-size...

Generalized and Unified Equivalences between Hardness and Pseudoentropy

Pseudoentropy characterizations provide a quantitatively precise demonstration of the close relationship between computational hardness and computational randomness. We prove a unified pseudoentropy characterization that generalizes and strengthens previous results for both uniform and non-unifor...

Leakage-Resilient Extractors against Number-On-Forehead Protocols

Given a sequence of $N$ independent sources $\mathbfX1,\mathbfX2,\dots,\mathbfXN\sim\0,1^n$, how many of them must be good i.e., contain some min-entropy in order to extract a uniformly random string? This question was first raised by Chattopadhyay, Goodman, Goyal and Li STOC '20, motivated by...

Optimized Couplings for Watermarking Large Language Models

Large-language models LLMs are now able to produce text that is, in many cases, seemingly indistinguishable from human-generated content. This has fueled the development of watermarks that imprint a signal'' in LLM-generated text with minimal perturbation of an LLM's output. This paper provides a...