Most cryptography patents pick a lane: a homomorphic-encryption patent, a key-exchange patent, a signature patent. US11394537B2, “Homomorphic encryption with quantum key distribution encapsulation,” granted to JPMorgan Chase Bank on July 19, 2022, is notable for stacking two frontiers at once — and the combination is the claim, not either piece alone.
The two ingredients solve different problems. Homomorphic encryption (CPC H04L 9/008) lets a party compute on encrypted data without decrypting it. Quantum key distribution (CPC H04L 9/0858) is a physics-based method of agreeing on a shared key whose security rests on quantum mechanics — any eavesdropper necessarily disturbs the quantum states and is detected. The patent claims using QKD to handle the key side of a homomorphic workflow.
Why pair them? Because they cover each other's exposed flank. Homomorphic encryption protects data in use but still depends on keys that have to be established and protected; QKD offers a key-establishment channel with a very strong, eavesdropper-evident security property. Encapsulating the homomorphic scheme's keys via QKD is, in concept, defense-in-depth across two independent threat models.
It is worth being clear-eyed about QKD. It requires specialized hardware and links and is not a drop-in replacement for software key exchange; it is a niche, infrastructure-heavy technology that banks and telecoms have piloted rather than broadly deployed. The patent is most interesting as a statement about where a frontier financial-cryptography group thought the puck was going, not as evidence of a mass-market product.
Per the desk's rules: issued grant (B2), not an application; method claim combining two techniques, not a shipped offering. The inventor team includes Pistoia and Polychroniadou, names associated with JPMorgan's well-publicized applied-cryptography and quantum research, which is the obvious context.
For the portfolio reader, the takeaway is that the most ambitious financial-cryptography IP of this period is integrative — combining homomorphic encryption, quantum key distribution, and post-quantum schemes into stacked systems. Whether or not any single stack ships, owning the combinations is a hedge across multiple possible futures.