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Key (MCK) |
|
Master Atalla Key | This key is used to XOR a value for PIN entry, MAC, or |
| encrypt/decrypt to form master variant keys to decrypt for PIN |
| entry, MAC, and COM session keys. |
9.4.3Session Keys
These keys are loaded encrypted under the corresponding master keys. This means that the type and index of the working (session) key have to match the type and index of the corresponding master key that was used to encrypt it. For application based financial keys, the SSA will have a key structure matrix indexed by application ID.
The device can accommodate up to ten working (session) keys per application, or up to 64 working (session) keys per terminal. Available indexes for the working (session) keys are 0
–9 per application or 0 – 64 per terminal. These keys can be both
Key Name | Description of Key |
Working (session) | This key is loaded encrypted under the corresponding Master |
Terminal PIN Key | Terminal PIN Key. It is used to encrypt the customer PIN for |
(WTPK) | transmission to the host. |
Working (session) | This key is loaded encrypted under the corresponding Master |
Message | Message Authentication Code Key. It is used to authenticate the |
Authentication | customer transaction. |
Code Key |
|
(WMACK) |
|
Working (session) | This key is loaded encrypted under the corresponding Master |
Communication | Communication Key. It is used to encrypt customer transaction |
Key (WCK) | data between the debit terminal and the host. |
|
|
Working (session) | This key is decrypted by the Master Atalla Variant Key, which is |
Atalla Key | created from the Master Atalla Key according to the type of |
| operation to be performed. |
9.4.4DUKPT Keys
The Initial PIN Pad Keys (IPPKs) are loaded encrypted under the KTK. The device can accommodate up to ten separate DUKPT engines. Each engine is initialized with an IPPK. Available indexes for the DUKPT engines are 0 – 9. The IPPKs can be both
9.5Security Options
This section provides a synopsis of each security option. All the security options can be loaded during key injection. The user application can request the security options setting from an SSA API.
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