About CardWise

CardWise is a free online platform providing developer tools for security engineers. We specialize in smart card, cryptography, NFC, and encoding utilities — built by engineers, for engineers.

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What We Do

CardWise provides a curated collection of online tools that security engineers use daily — from parsing EMV TLV data to computing HMAC signatures, from building APDU commands to decoding X.509 certificates.

Every tool runs entirely in your browser. Your data never leaves your device. No signup, no API keys, no server-side processing.

Our Tools

Smart Card & NFC

APDU Command Builder — Interactive ISO 7816-4 APDU construction with presets
EMV TLV Parser — BER-TLV decode with EMV tag search and DOL builder
ATR Decoder — Parse Answer-To-Reset, auto-detect T=0/T=1
GP Session Key Calculator — SCP02/SCP03 key derivation and MAC computation
NDEF Parser, NFC Tag Detector, MIFARE Access Bits — Full NFC tooling

Cryptography & Security

AES / SM4 Encryption — Symmetric encryption with CBC/GCM modes
RSA Asymmetric — Key generation, OAEP encrypt/decrypt, PKCS#1 sign/verify
SM2 Chinese Crypto — National standard elliptic curve operations
HMAC Generator & Verifier — HMAC-MD5/SHA1/SHA256/SHA384/SHA512
JWT Decoder, X.509 Cert Parser, Hash Digest — Essential crypto utilities

Encoding & Data

Base64 Encoder / Decoder — Standard, URL-safe, MIME variants
URL Encoder / Decoder — Component, Full URL, and Batch modes
CRC Calculator, Luhn Validator, ASN.1 DER Parser — Data format tools

Our Values

🔒 Privacy by design. All computation happens client-side. Your keys, certificates, and data never leave your browser.

🚀 Fast and focused. No bloated frameworks. Pure HTML/CSS/JS pages that load instantly and work offline after first visit.

📚 Standards-first. We reference ISO, EMVCo, NIST, GlobalPlatform, and IETF RFCs. Every tool cites the relevant specification.

🆓 Free forever. No paywalls, no signup walls, no "premium" tiers. These are developer tools — they should be free.

Who Built This

CardWise is built and maintained by a small team of smart card and security engineers with decades of combined experience in:

SIM / eSIM card development and testing (ETSI, GSMA, 3GPP)
Financial IC card and EMV contactless payment systems
GlobalPlatform secure element management
FIDO2 / WebAuthn authentication
National cryptography (SM2/SM3/SM4) and PKI

We built CardWise because we were tired of switching between desktop applications, Python scripts, and hex calculators just to decode an ATR or verify a session key. Now all those tools live in one place — your browser.

CardWise is the English-language edition of 卡智通 (Cupass), a smart card engineering platform serving the Chinese developer community since 2024.

Technology

Frontend: Pure HTML5 + CSS3 + vanilla JavaScript (no frameworks, no build step)
Cryptography: Web Crypto API, SubtleCrypto, and proven open-source libraries
Hosting: Static files on Alibaba Cloud ECS, delivered via Cloudflare CDN
Analytics: Google Analytics 4 (with IP anonymization enabled)