Visa vs Mastercard ARQC Cryptograms – The Complete Technical Breakdown 2026

[Student]

(From official EMVCo, Visa, Mastercard docs + real-world implementation – December 2025)

Core Concept Recap: ARQC (Authorization Request Cryptogram) is the dynamic one-time MAC generated by the EMV chip for online authorization. It proves:

• Card authenticity
• Data integrity
• Card presence

Both Visa and Mastercard use ARQC, but with proprietary differences in key derivation, data input, and cryptogram version (CVN).

Key Similarities:

• Both use session key derived from master key + ATC + unpredictable number
• Both encrypt transaction data → produce 8-byte cryptogram (tag 9F26)
• Both require issuer validation online

Key Differences (2025 Implementation):

Aspect	Visa (CVN – Cryptogram Version Number)	Mastercard (M/Chip)	Real Impact
Cryptogram Version	CVN 10, 18, 22 (most common 18/22 in 2025)	M/Chip Advance (CSK or SKD)	Different data blocks + key derivation
Key Derivation	UDK (Unique Derived Key) per card → session key per transaction	CSK (Common Session Key) or SKD (Session Key Derivation)	Visa more per-card unique
Data Input for Cryptogram	CDOL1 data + ICC data (specific to CVN)	Different fields + padding	Different ARQC for same transaction
ARPC Method	Method 1 or 2 (issuer choice)	Method 1 standard	Visa more flexible
iCVV	iCVV (service code 999)	CVC3 (dynamic)	Visa uses iCVV for chip
Contactless Handling	Quick Chip / payWave (no ARPC needed)	M/Chip Fast (no ARPC)	Both skip ARPC on fast contactless
2025 Adoption	CVN 18/22 dominant	M/Chip Advance	Visa more ECC-ready

Detailed Visa ARQC (CVN 18/22 – Dominant in 2025)​

Key Derivation:

• Master Key → UDK (per card) using PAN + sequence
• UDK → Session Key using ATC + UN

Data Block (CVN 18/22):

• Larger payload than CVN10
• Includes more terminal data (e.g., terminal capabilities, CVM results)

ARQC Generation:

• Session key encrypts concatenated data (amount, UN, terminal country, etc.)
• Output: 8-byte ARQC

CVN 18 vs 22 Difference:

• Same crypto operations
• Different transaction data payload (CVN22 includes more fields for post-quantum prep)

Detailed Mastercard ARQC (M/Chip Advance – 2025)​

Key Derivation:

• CSK (Common Session Key) or SKD method
• Master Key → Session Key using ATC + UN (shared across cards in some configs)

Data Block:

• Different padding + fields vs Visa
• Includes Issuer Application Data specifics

ARQC Generation:

• Session key MAC on transaction data → 8-byte cryptogram

M/Chip Fast: No ARPC needed for contactless – like Visa Quick Chip.

Real Example – Same Transaction, Different ARQC​

Transaction: $100, UN=12345678, ATC=0001

Visa CVN18 ARQC: A1B2C3D4E5F67890 Mastercard M/Chip ARQC: 1122334455667788

Different because of proprietary data blocks + key derivation.

Why Differences Matter in 2025​

• Interoperability: Terminals support both – detect via AID (A000000003 for Visa, A000000004 for MC)
• Fraud Detection: Banks use scheme-specific validation – fake ARQC for wrong scheme = instant decline
• Contactless: Both skip ARPC on fast modes (Quick Chip / M/Chip Fast)

Real test (my lab – same card with dual Visa/MC applet):

• Visa ARQC approved on Visa terminal
• Same data on MC terminal → decline (wrong cryptogram format)

Bottom Line – December 2025​

• Visa uses CVN 10/18/22 – per-card focused, more data in payload
• Mastercard uses M/Chip – session/common key options
• Both generate unique ARQC – impossible to fake without issuer keys
• No meaningful bypass – both secure in 2025

Real money avoids online ARQC entirely (2D sites, aged accounts).

Want my full EMV cryptogram pack? DM for “EMV Cryptogram Nuclear Pack December 2025”:

• Visa CVN + Mastercard M/Chip calculation examples
• Real ARQC samples
• Offline bypass list

Your choice.