# SessionKeyDerivationValue
<a name="API_SessionKeyDerivationValue"></a>

Parameters to derive session key value using a MAC EMV algorithm.

## Contents
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**Important**  
This data type is a UNION, so only one of the following members can be specified when used or returned.

 ** ApplicationCryptogram **   <a name="paymentcryptographydata-Type-SessionKeyDerivationValue-ApplicationCryptogram"></a>
The cryptogram provided by the terminal during transaction processing.  
Type: String  
Length Constraints: Fixed length of 16.  
Pattern: `[0-9a-fA-F]+`   
Required: No

 ** ApplicationTransactionCounter **   <a name="paymentcryptographydata-Type-SessionKeyDerivationValue-ApplicationTransactionCounter"></a>
The transaction counter that is provided by the terminal during transaction processing.  
Type: String  
Length Constraints: Fixed length of 4.  
Pattern: `[0-9a-fA-F]+`   
Required: No

## See Also
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For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/payment-cryptography-data-2022-02-03/SessionKeyDerivationValue) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/payment-cryptography-data-2022-02-03/SessionKeyDerivationValue) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/payment-cryptography-data-2022-02-03/SessionKeyDerivationValue)