https://www.youngju.dev/blog 천천히 올바르게. AI Researcher & DevOps Engineer Youngju's tech blog. GPU/CUDA, LLM, MLOps, Kubernetes AI workloads, distributed training, and data engineering. ko fjvbn2003@gmail.com (Youngju Kim) fjvbn2003@gmail.com (Youngju Kim) Mon, 25 May 2026 00:00:00 GMT https://www.youngju.dev/blog/culture/2026-05-25-payment-infrastructure-visa-mastercard-stripe-adyen-paypal-toss-naver-kakao-paypay-line-rakuten-2026-deep-dive.en https://www.youngju.dev/blog/culture/2026-05-25-payment-infrastructure-visa-mastercard-stripe-adyen-paypal-toss-naver-kakao-paypay-line-rakuten-2026-deep-dive.en Payment infrastructure in 2026 is no longer the story of "a single card." Stripe and Adyen, perched atop the two enormous 4-party networks of Visa and Mastercard, each push `$1T+ TPV`; the US, EU, and Asia run on different rule sets (Durbin, PSD2, Korean specialized credit finance act); Korea has 40M Toss Pay, 30M Naver Pay, and 45M Kakao Pay users living alongside credit cards; and in Japan PayPay (65M users) has absorbed LINE Pay and built a new QR rail next to the JPY 90T credit-card market. This article walks, in a single breath, from the grammar of payments (4-party model, ISO 8583, interchange fee, 3D Secure 2.0, SCA, tokenization) to the topology of 50 global, Korean, and Japanese players. Mon, 25 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) paymentsvisa-networkmastercard-banknetamexunionpayjcbstripeadyensquare-blockpaypalworldpaywisetoss-paynaver-paykakao-paypaypayline-payrakuten-paydocomo-d-barai3d-secure-2 https://www.youngju.dev/blog/culture/2026-05-25-payment-infrastructure-visa-mastercard-stripe-adyen-paypal-toss-naver-kakao-paypay-line-rakuten-2026-deep-dive.ja https://www.youngju.dev/blog/culture/2026-05-25-payment-infrastructure-visa-mastercard-stripe-adyen-paypal-toss-naver-kakao-paypay-line-rakuten-2026-deep-dive.ja 2026年の決済インフラはもはや「カード一枚」の話ではない。Visa・Mastercardという二大4-partyネットワークの上に Stripe や Adyen といった PSP が `$1T+ TPV` を回し、米・欧・アジアがそれぞれ違う規制(Durbin・PSD2・韓国の与信専門金融業法)で縛られ、韓国は Toss Pay 4,000万・Naver Pay 3,000万・Kakao Pay 4,500万人がクレジットカードと同居し、日本は PayPay 6,500万人が LINE Pay を吸収しながら、90兆円のクレカ市場の隣に新しい QR レールを敷いた。本稿は 4-party モデル・ISO 8583・interchange fee・3D Secure 2.0・SCA・tokenization といった決済の基本文法から、グローバル・韓国・日本の50プレイヤーの位置関係までを一気に整理する。 Mon, 25 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) paymentsvisa-networkmastercard-banknetamexunionpayjcbstripeadyensquare-blockpaypalworldpaywisetoss-paynaver-paykakao-paypaypayline-payrakuten-paydocomo-d-barai3d-secure-2 https://www.youngju.dev/blog/culture/2026-05-25-payment-infrastructure-visa-mastercard-stripe-adyen-paypal-toss-naver-kakao-paypay-line-rakuten-2026-deep-dive https://www.youngju.dev/blog/culture/2026-05-25-payment-infrastructure-visa-mastercard-stripe-adyen-paypal-toss-naver-kakao-paypay-line-rakuten-2026-deep-dive 2026년의 결제 인프라는 더 이상 "카드 한 장"의 이야기가 아니다. Visa·Mastercard라는 두 거대한 4-party 네트워크 위에 Stripe·Adyen 같은 PSP가 얹혀 `$1T+ 처리량`을 굴리고, 미국·유럽·아시아 각각이 다른 규제(Durbin·PSD2·전금법)로 묶이고, 한국은 토스페이 4000만·네이버페이 3000만·카카오페이 4500만이 신용카드와 동거하고, 일본은 PayPay 6500만이 LINE Pay를 흡수하면서 신용카드 90조엔 시장 옆에 새로운 QR 레일을 깔았다. 이 글은 4-party 모델·ISO 8583·interchange fee·3D Secure 2.0·SCA·tokenization 같은 결제의 기초 문법부터 글로벌·한국·일본 플레이어 50개의 위치 관계까지를 한 호흡으로 정리한다. Mon, 25 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) paymentsvisa-networkmastercard-banknetamexunionpayjcbstripeadyensquare-blockpaypalworldpaywisetoss-paynaver-paykakao-paypaypayline-payrakuten-paydocomo-d-barai3d-secure-2