The most consequential crypto-adjacent IP is rarely the patent that says “blockchain” in its title. It is the unglamorous plumbing — tokenization, controlled numbers, account-to-rail mapping — because that plumbing is where on-chain value will eventually have to plug into the card networks that already move trillions. Mastercard's US12,198,133, granted January 14, 2025, is exactly that kind of grant, and the landscape it sits in is the story.

The claimed method is a handoff. The verbatim opening pins the recited flow.

A method for supplying a controlled payment number for use on behalf of a tokenized payment account in a digital wallet for e-commerce includes: receiving, by a wallet server, at least a token identifier from an external computing device, the token identifier being associated with a tokenized payment account in the external computing device.

From there the sequence is tight: the wallet server transmits the token identifier and a request flag to a processing server; the processing server identifies the transaction account number associated with the token, identifies a controlled payment number corresponding to that account, and returns it; the wallet server then transmits the controlled payment number back to the external device. The controlled payment number is the operative concept — a constrained, single-purpose surrogate that can be limited by amount, merchant, or time, so the real account number is never exposed at the point of e-commerce.

The landscape read is why this belongs in Grant Watch rather than a claim teardown. This grant does not stand alone. The same Mastercard assignee holds US12,393,945, a payment-processing patent built on “distributed digitized surrogates,” which fences the broader surrogate-credential machinery from a different angle. Across the tokenization cluster, the patent records assignee facets put Mastercard among the most active filers alongside Visa, Block, and Royal Bank of Canada — the incumbents, not the crypto startups, are the ones thickening this layer.

The CPC clustering confirms the lane. US12,198,133 sits in G06Q 20/401 (transaction verification), G06Q 20/36 (e-wallet/e-money), G06Q 20/3821 (verification of transaction security), and G06Q 20/385 (payment protocols using an alias/token). This is squarely the payments-and-tokenization corner of G06Q 20 — the same CPC neighborhood that crypto custody and stablecoin-settlement patents increasingly share. That overlap is the point: as stablecoin and tokenized-deposit settlement matures, it will be adjudicated in this exact classification space, against estates the card networks have been quietly building for years.

What this is not: a blockchain patent, and not a claim that Mastercard owns tokenized wallets. The grant is bounded by its specific server-to-server token-to-controlled-number flow with the recited request flag and account mapping. A wallet that provisions credentials by a different mechanism, or that never resolves to a controlled payment number, reads outside it. The honest scope here is narrow — one handoff in a much larger payment stack.

It helps to understand why the controlled payment number is the conceptual center of gravity, because it is also the bridge to the crypto story. A controlled payment number is a constrained surrogate — usable once, or capped, or merchant-locked — standing in for a real account so the real credential never travels. That is structurally the same idea as a single-use on-chain address, a session key, or a constrained spending authorization in a smart-contract wallet: expose a limited, revocable proxy rather than the underlying secret. When card networks and crypto custody converge, they will converge on this shared primitive of constrained surrogate credentials, and the assignee that has patented the surrogate-issuance plumbing in G06Q 20 will have leverage regardless of which rail the value ultimately rides.

A scope-honest reader should still keep the controlled-number flow distinct from the broader tokenization vocabulary it sits inside. "Tokenization" in payments — replacing a primary account number with a surrogate token — is decades-old EMVCo-standardized practice, and this grant does not own it. What it recites is a specific server-mediated path: token identifier plus request flag in, account lookup, controlled-number out, returned to the device. The novelty is in the orchestration of that handoff, not in the existence of tokens or controlled numbers individually. That distinction is exactly the kind of thing that separates a defensible claim from a marketing line about "owning tokenization," and it is why reading the recited sequence matters more than the title.

But the assignee pattern is the durable signal, and it is what a portfolio reader should carry away. Mastercard is methodically patenting the connective tissue between tokenized accounts and its existing rails. When the conversation turns to “stablecoins will settle on card networks” or “tokenized deposits will ride existing payment infrastructure,” the relevant question is not who has the flashiest chain — it is who owns the surrogate-credential and tokenization plumbing those flows will have to traverse. On current evidence, the card incumbents have a head start, and grants like this one are how they keep it. The inventors named, Liam Spence, Skyler Fox, and Joseph Hayes, are building that connective layer; the canonical records for both this grant and its sibling are deep-linked above for readers who want to walk the claim sets and see the thicket forming.