TAV Clock Cryptography: A Stateful Cryptographic System Based on Ephemeral Structure and Continuous Physical Entropy

Abstract We present TAV (Transactional Asynchronous Verification), an innovative cryptographic system that integrates continuous physical entropy collection, stateful stream cipher, message authentication, and digital signatures into a unified, self-contained architecture. Unlike conventional approaches that use physical entropy solely as a seed source for mathematical constructions--such as Jitterentropy feeding SHA3-256 for conditioning--TAV embeds physical measurements throughout its entire operation using exclusively logic operations (XOR, AND, OR, bit rotation), requiring no external cryptographic primitives. The core innovation is the concept of 'ephemeral structure': TAV has algebraic structure (1,464 prime numbers, transactional clocks, cryptographic keys), but this structure changes unpredictably with each operation. Four independent clocks with coprime prime periods (17, 23, 31, 47) govern state transitions across six 'prime boxes'. By the Chinese Remainder Theorem, the global state cycle reaches 563,327 transactions before any repetition in clock states alone. Combined with continuous entropy injection, the effective state space exceeds 6x10^22 configurations. TAV provides two digital signature schemes: Hash-Chain (Lamport-style) with 66-byte signatures and Commitment-Reveal with 72-byte signatures--both dramatically smaller than ML-DSA (2,420-4,627 bytes). The system also supports self-signed certificates for identity management. A unique property of TAV is that each instance's state serves as a device fingerprint, enabling fraud prevention and content authenticity verification. Version 0.9 introduces automatic encrypted checkpointing every 10,000 transactions, a threat management system with dynamic security escalation, and dead-man switch protection. Complete implementations are provided in Python, C, JavaScript, Rust, and Arduino/ESP32, with cross-platform interoperability validated through comprehensive test suites. Performance evaluation shows complete system throughput of ~500-850 KB/s depending on security level, with isolated keystream achieving ~5 MB/s--comparable to ChaCha20 in pure Python. Shannon entropy of 7.996 bits/byte (99.95% of theoretical maximum), bit bias of only 0.15%, and autocorrelation below 0.001. TAV deliberately avoids modular addition--the "A" in the ARX paradigm used by ChaCha20, Salsa20, BLAKE, and Skein--thereby eliminating susceptibility to rotational cryptanalysis. For constrained IoT devices, TAV offers significant advantages: zero network round-trips for key establishment (stateful), minimal memory footprint (~500 bytes RAM), small key sizes (16-32 bytes vs 1,184-1,568 bytes for ML-KEM), and complete self-containment without external cryptographic dependencies. We emphasize that TAV is experimental research software without formal security proofs or independent audits. We do not claim proven security or superiority over established algorithms. Rather, we present TAV as an alternative approach with fundamentally different trade-offs, inviting community analysis. The complete source code, test vectors, and documentation are available under AGPL-3.0 license with a commercial grace period until May 2027. Keywords: stateful stream cipher, ephemeral structure, digital signatures, device identity, physical entropy, CPU timing jitter, logic-only cryptography, post-quantum considerations, Feistel network, prime-period clocks, IoT cryptography, fraud prevention