CryptoHorizon an interactive app that makes the quantum threat to encryption real instead of theoretical: a live Shor's-algorithm demo, a classical-vs-post-quantum crypto benchmark, a personal "harvest now, decrypt later" risk calculator, and a sourced Q-Day timeline, all in one dashboard. Defining feature is honesty by design: every number on screen is computed live at request time, never hardcoded RSA-2048 and ECC P-256 keys get generated, benchmarked, and compared against NIST's ML-KEM and ML-DSA in real time, and the quantum demo runs an actual Qiskit circuit against small, pre-validated semiprimes rather than a lookup table dressed up as a result. Only one thing is allowed to leak into the UI's language: a rule baked in from commit one that nothing may imply real-world RSA is broken or claim quantum advantage. Under the hood, Shor's algorithm runs for real superposition over a counting register, controlled modular exponentiation, inverse QFT, continued-fraction extraction, then a classical gcd step to pull out the factors on a FastAPI backend with no shortcuts. The risk calculator checks your required confidentiality window against five independently sourced Q-Day estimates from NIST, Google, and the Global Risk Institute, so "safe until 2035" is a real, cited comparison, not a guess. medium.com/@anuragnagare77/cryptohorizon-i-built-a-quantum-computer-that-factors-91-and-thats-the-whole-point-2c156a00d0da