Host Protocols Direct Protocol PROTOCOL class CHANGE KEY
September 3, 2025 at 8:28 AMCHANGE KEY instruction
The CHANGE KEY instruction allows to change either the HostCommUserKey or the HostCommAdminKey
INS value
INS = 0C
Command
| Field | Value | Explanations |
|---|---|---|
| CLA | 00 |
Class = PROTOCOL |
| INS | 0C |
Instruction = CHANGE KEY |
| Data byte 0 | 01 |
Authentication version & mode: AES128 |
| Data byte 1 | 0001 |
User access (KAUTH = HostCommUserKey) Admin access (KAUTH = HostCommAdminKey) |
| Data bytes 2 to 17 | New key value |
Response
| Field | Value | Explanations |
|---|---|---|
| CLA | 00 |
Class = PROTOCOL |
| STA | 00 |
Success |