Searchable reference databases for the bytes you stare at every day.
12 reference databases — status words, tags, OIDs, AAGUIDs, ISO field meanings — with client-side search, category filters, and deep-linkable entries. No accounts. No ads. Nothing leaves your browser.
Pair with the tool catalogue when you need to walk live bytes.
Smart-card & APDU protocol
APDU Status Words
ISO/IEC 7816-4 standard status words plus GlobalPlatform, EMV, and FIDO U2F additions. Search by code or by phrase.
48 entries → ISO 7816-4ISO 7816 CLA Values
Common ISO/IEC 7816-4 CLA byte values. Interindustry, proprietary, GlobalPlatform, and secure-messaging variants — with the bit-level breakdown.
10 entries → GlobalPlatform 2.3.1GlobalPlatform Status Words
Status words returned by GlobalPlatform 2.3.1 card-management commands (INSTALL, LOAD, DELETE, GET STATUS, GET DATA). GPC §11.
20 entries → JavaCardJavaCard CAP Components
The 12 component types inside a JavaCard CAP file. Mandatory vs optional, what each carries, and what the on-card verifier checks.
12 entries →ASN.1 & PKI encoding
ASN.1 Universal Tags
Universal-class tag identifiers from ITU-T X.680, with primitive vs constructed form. The encoding floor underneath X.509, PKCS, CMS, FIDO attestation, EMV PKI.
16 entries → X.509 / PKIXX.509 / Certificate OIDs
RDN attribute types (CN, O, C), certificate extensions (KU, EKU, SAN, BC), signature algorithms — the OIDs that appear inside a DER-encoded certificate.
30 entries → X.509 / PKIXX.509 Extensions
Common X.509 v3 extensions — what they are, criticality, and what they encode. Pair with the X.509 viewer to walk live certs.
13 entries →FIDO / WebAuthn
WebAuthn COSE Algorithms
COSE algorithm identifiers used by WebAuthn and FIDO2. ES256 (-7) is the default; EdDSA (-8) and RS256 (-257) appear in older stacks.
FIDO AAGUIDs
Curated AAGUID directory. Search by vendor, model, or AAGUID. Production deployments should fetch the FIDO MDS BLOB for authoritative metadata.
25 entries →EMV & transit
EMV Tags
Searchable EMV tag reference. Books 3, 4, and Contactless. Filter by category to narrow down to the tags you need.
56 entries → NXP DESFireDESFire Status Codes
Documented DESFire EV1/EV2/EV3 response status codes with meaning and context. Search by code or by phrase.
22 entries →NFC / NDEF
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