Kryptos K4 — Core Dataset v1 (Running-Key Reconstruction)

This dataset contains the core, machine-readable artifacts required to independently verify a publicly released candidate reconstruction of the Kryptos K4 cipher. It includes a complete 1–97 ciphertext index scaffold, an explicit structural null and header mask, an 86-character running-key stream, and a provenance-mapped key-letter table derived from historically grounded Cold War–era sources. The dataset is intentionally limited to verifiable data structures and does not depend on narrative interpretation. Companion documents describing the abstract, derivation, and generative method are published separately on SSRN and GitHub. This dataset is provided to support independent cryptanalytic verification, replication, and scholarly review.