6 min read
AI Sycophancy: Your Model Is Trained to Please You, Not to Be Right
There’s a quiet failure mode in AI-assisted engineering that most people don’t talk about: sycophancy. It’s the tendency of large language models to prioritize …
Payments architecture · EMV · AI systems
Corebaseit
I’m Vincent Bevia. I work in payments at MultiSafepay (part of Ant Group), and I’ve spent years focused on POS architecture, EMV, and cryptography. I’m also the author of Point-of-Sale Systems Architecture: A Practical Guide to Secure, Certifiable POS Systems and The Obsolescence Paradox: Why the Best Engineers Will Thrive in the AI Era.
This blog is my space to share what I’m thinking about, learning, and discussing: POS systems, EMV, Payment Security, and, increasingly, about AI in general and how AI is reshaping this field. I also draw on my background in Electrical Engineering and Telecommunications — information theory, stochastic processes, and thermodynamics — the technical foundations that sit beneath much of this work.
Less corporate, more personal. Opinions, reflections, and the kind of things I’d talk about over coffee.
Topics I care about
- POS & EMV — how terminals, chips, and contactless payments actually work
- Cryptography & security — DUKPT, HSMs, and key management in the real world
- AI in payments — where it helps, where it doesn’t, and what’s coming next
- Engineering foundations — telecommunications, information theory, and stochastic processes
If you’re building payment technology — or just curious about how it all fits together — welcome.
Latest field notes
Writing at the edge of payments, security, DSP, and AI
6 min read
Prompt Engineering for POS: Treating LLM Inputs as First-Class Architecture
When we talk about AI in payments, the conversation often jumps to chatbots and support agents. But the real leverage — especially in regulated environments like SmartPOS and …
13 min read
DUKPT Key Derivation: Technical Reference for POS Systems
Derived Unique Key Per Transaction (DUKPT) is the cryptographic foundation that makes secure payment terminals possible. Without DUKPT, every transaction would require transmitting …
5 min read
PIN Translation: Bridging Cryptographic Worlds Inside the HSM
When a cardholder enters their PIN at a modern SmartPOS terminal, something subtle but critical happens behind the scenes. The terminal encrypts that PIN using AES and formats it …
7 min read
EMV Cryptograms: How ARQC Prevents Fraud
Every time you tap or insert a chip card, the card generates a unique cryptogram — a cryptographic proof that this specific transaction is legitimate and hasn’t been seen …
7 min read
RSA Algorithm: Theory and Implementation
Author: Vincent Bevia, MSc Computer Science — University of Liverpool Introduction RSA (Rivest–Shamir–Adleman) is one of the first public-key cryptosystems and is widely used for …
5 min read
Nexo Protocol Adoption in Modern SmartPOS Architectures
Modern payment terminal architectures increasingly rely on standardized protocols to reduce integration costs, ensure interoperability, and simplify expansion across markets. …
5 min read
Types of POS Terminals and Where They Fit
Types of POS Terminals, the Services They Offer, and Where They Fit Modern POS environments are built from a small number of terminal families, each tuned to a specific risk …
1 min read
IPEK Derivation & Terminal Key Injection
This page shows a full interactive layout explaining DUKPT / IPEK derivation and terminal key injection. The interactive example is anchored in the key-management and POS security …
3 min read
Track 2 Data — Technical Overview (and Why It's Slowly Disappearing)
Track 2 is the numeric-only magnetic-stripe data format defined in ISO/IEC 7813, with a maximum length of 40 characters. The discussion here complements the broader POS and EMV …