9F79
Unprotected Data Envelope 5Unprotected Data Envelope 5 shares the exact same free-read, not integrity-protected design as its sibling Unprotected Data Envelope 2 (9F76), but sits in a different position in Kernel 2's numbered envelope family: where 9F76 is bracketed by two neighbours (9F75 and 9F77) in the sequence, 9F79 relates only to 9F75, suggesting a more standalone slot rather than a tightly clustered one. What that difference in numbering and relation doesn't change is the operational caution both envelopes deserve equally: because unprotected means exactly what it says, any application reading 9F79 is choosing to trust its content without a cryptographic basis for that trust, which is a legitimate design choice for genuinely low-stakes data but a real liability if a terminal or host implementation ever mistakenly treats it as authenticated. Like 9F76, this is a Mastercard PayPass (Kernel 2) tag, absent by design from other kernels' data models rather than merely missing from a specific card. See EMV Contactless Book C-2.
Interactive decoder
Paste a hex value for this tag to decode it in your browser. Nothing is sent anywhere.
Binary (3): 0A0B0C
This tag is not a bitmap; the decoder shows a format-based interpretation.
Decoded example
Example value: 0A0B0C
Related tags
Properties
| Tag | 9F79 |
|---|---|
| Name | Unprotected Data Envelope 5 |
| Format | Binary |
| Length | variable |
| Source | Card (ICC) |
| Templates | — |
| Books | EMV Contactless Book C-2 |
Frequently asked questions
- What is EMV tag 9F79?
- Unprotected Data Envelope 5 shares the exact same free-read, not integrity-protected design as its sibling Unprotected Data Envelope 2 (9F76), but sits in a different position in Kernel 2's numbered envelope family: where 9F76 is bracketed by two neighbours (9F75 and 9F77) in the sequence, 9F79 relates only to 9F75, suggesting a more standalone slot rather than a tightly clustered one. What that difference in numbering and relation doesn't change is the operational caution both envelopes deserve equally: because unprotected means exactly what it says, any application reading 9F79 is choosing to trust its content without a cryptographic basis for that trust, which is a legitimate design choice for genuinely low-stakes data but a real liability if a terminal or host implementation ever mistakenly treats it as authenticated. Like 9F76, this is a Mastercard PayPass (Kernel 2) tag, absent by design from other kernels' data models rather than merely missing from a specific card. See EMV Contactless Book C-2.
- What format and length does EMV tag 9F79 use?
- Tag 9F79 uses the Binary format and is normally variable long.
- Is tag 9F79 provided by the card or the terminal?
- Tag 9F79 (Unprotected Data Envelope 5) is provided by the Card (ICC).
Sources
- C-2-Kernel-2-V2.11-Final-June-2023, p. 435
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