The cryptographic locks protecting trillions of dollars in digital assets were designed for a world without quantum computers. That world is ending faster than most people in crypto realize, and the industry's response is still dangerously fragmented. NIST finalized its first three post-quantum cryptography standards in August 2024 and told every organization using public-key cryptography to begin migration immediately. Bitcoin (BTC) alone holds roughly $1.57 trillion in market capitalization, and the vast majority of that value is secured by elliptic curve digital signature algorithms that a sufficiently powerful quantum computer could break. The clock is running. TL;DR - NIST's 2024 post-quantum standards mark a hard deadline for crypto projects to begin migration away from elliptic curve cryptography or face existential security risk. - An estimated 4 million BTC sitting in exposed P2PK outputs or reused addresses could be directly vulnerable once cryptographically relevant quantum computers arrive. - Most major blockchains have no binding post-quantum upgrade roadmap, creating a fragmented and time-pressured security landscape heading into the late 2020s. 1. The Quantum Threat to Blockchain Is Specific, Not Theoretical The phrase "quantum threat" gets thrown around loosely, but for blockchain specifically the danger is precise and well-documented. Two algorithms sit at the core of most blockchain security- the Elliptic Curve Digital Signature Algorithm (ECDSA), used to authorize transactions, and SHA-256, used in Bitcoin's proof-of-work mining. These face very different levels of quantum risk. Shor's algorithm, developed in 1994, can factor large integers and solve the discrete logarithm problem in polynomial time on a quantum computer. A paper published on arXiv in 2023 by researchers at the University of Sussex estimated that breaking Bitcoin's 256-bit elliptic curve encryption would require a quantum computer with roughly 317 million physical qubits operating with low error rates. Grover's algorithm, by contrast, offers only a quadratic