Use test data. No commands are sent to a card.
UDK
TDES Option A with odd parity.
LUK
Published patent / tutorial profile: TDES encrypts 1YHHHHCC80000000 and 2YHHHHCC80000000 under the UDK. Raw key bytes are concatenated without parity adjustment. Y is the final year digit; HHHH is hours since year start, not the clock hour. This matches the supplied example, not a claim of compliance with every VCPCS version.
qVSDC
Tutorial TDES retail-MAC profile: terminal bytes followed by ICC bytes, with ISO 9797 padding method 2. Supply the LUK directly; no wallet provisioning or card emulation is performed.
Calculator reference
Verification evidence and limitations →
What it calculates
UDK, LUK and qVSDC calculations.
Inputs and methods
Enter the HEX and decimal fields labelled on each tab. Profile-specific lengths are enforced.
Worked example
Worked UDK example: MDK · HEX, 16 bytes: 0123456789ABCDEFFEDCBA9876543210; PAN · decimal digits: 4111111111111111; PAN sequence number · 2 digits: 00
UDK: 31089464674C73EC851A6E0737029D19 KCV: 9595D5
Specification and limits
This demonstrates the first tab only. Other stages need their own profile inputs; outputs do not prove issuer authorization.
Visa specification library ↗