DDA Validator

Recover issuer and ICC public keys, then verify the dynamic signature.

Inputs

Key recovery

Select a trusted CA key using the RID and CA key index (8F). Successful recovery fills the next tab’s public key. Each stage can also be used with a manually supplied key.

Static data

For ICC certificate recovery, supply static authentication bytes assembled in AFL order, including any AIP value required by 9F4A. This is not an unordered TLV dump.

DDOL-related data

Paste the exact data bytes sent in INTERNAL AUTHENTICATE, in DDOL order. Exclude the APDU header, Lc, Le, tags and lengths. Use the unpredictable number alone only when that is the complete DDOL input.

Verification scope

Signature verification checks the supplied key and bytes. It does not establish CA trust, revocation status, or freshness of a previously captured exchange. PAN and expiry checks are optional and reported separately.

Supported profile

Classic EMV RSA/SHA-1 DDA (format 05), exponents 03 or 010001, keys up to 248 bytes. CDA, fast DDA and ECC are not supported.

EMV Book 2, §§6.3-6.5 (EMVCo specifications) ↗

Calculator reference

Verification evidence and limitations →

What it calculates

Recovers issuer and ICC public keys and verifies a dynamic card signature.

Inputs and methods

RSA certificates, exponents, remainders, signed dynamic data and the exact DDOL input bytes.

Worked example

Load the built-in synthetic example and run issuer recovery, ICC recovery and signed-data verification.

Dynamic signature: verified

Specification and limits

Only the supplied chain and signed bytes are checked. Terminal trust, revocation and live-card communication remain outside this tool.

EMV specifications ↗