EMV StackBlog
EMV articles
Clear explanations of how chip card transactions work, written for developers, testers and product teams. New to a term? See the EMV glossary.
Why APIs Matter in EMV: The Missing Level 2 API
EMV standardises the card, the kernel and the tests, but not the API between payment application and Level 2 kernel, nor a hardware abstraction layer. Why that matters.
EMV Level 2 vs Level 3: What Each Certification Covers
The difference between EMV Level 1, Level 2 and Level 3 certification: what is tested, who approves it, what triggers new testing and why Level 3 fails.
Kernel 2 vs Kernel 3: Mastercard and Visa Contactless Compared
How Mastercard's Kernel 2 and Visa's Kernel 3 differ: when the cryptogram is made, CDA vs fDDA, CVM logic, terminal action analysis and configuration.
What Is an ARQC? The EMV Online Cryptogram Explained
How the card builds the Authorisation Request Cryptogram, which data and keys go into it, how the issuer validates it and why validation fails.
EMV Kernel 8 Explained: EMVCo's Common Contactless Kernel
What Kernel 8 is, why it matters, how its ECC secure channel and privacy protection work, and what changes for terminal developers.
EMV TLV Explained: How Card Data Is Encoded
How EMV cards encode data as Tag-Length-Value objects: tag bytes, length forms, templates and a worked example you can paste into the parser.
TVR Explained: Every Bit of Tag 95
What the Terminal Verification Results mean byte by byte, how they relate to the TSI, and how the terminal uses them to approve, decline or go online.