电能表预付费系统-标准传输规范(STS)（40）

7.3.4 DEA: DecryptionAlgorithm09

This algorithm is deprecated and shall not be used in new products.

        此算法已被弃用，不得用于新产品。

7.3.5 MISTY1 : DecryptionAlgorithm11

7.3.5.1 Decryption process

The decryption process using the MISTY1 is shown in Figure 26.

        使用MISTY1的解密过程如图26所示。 

        解密算法和加密算法是互补的，因而共享相同的EA代码。

7.3.5.2 Worked example to decrypt a TransferCredit token using the MISTY1

A worked example is illustrated in Figure 27.

        图27展示了一个实例。

 7.3.6 TokenAuthentication

 Validating the CRC or the CRC_C checksum after decryption shall authenticate Class 0 and Class 2 tokens.

         对解密后的CRC或CRC_C校验和进行验证，对0类和2类token进行验证。

 Validating the CRC and the MfrCode shall authenticate Class 1 tokens.

         验证CRC和MfrCode应验证第1类令牌。

 In the case of a Class 0 or a Class 2 token the AuthenticationResult status shall indicate Authentic when the following condition is met:

        在0类或2类令牌的情况下，当满足以下条件时，AuthenticationResult状态应表明真实性：

 • the CRC or CRC_C checksum in the token has the same value as that calculated from the data elements in the token.

• 令牌中的CRC或CRC_C校验和与根据令牌中的数据元素计算出的值相同。

If the above condition is not met, then the AuthenticationResult status shall indicate CRCError.

        如果上述条件不满足，则AuthenticationResult状态为CRCError。
In the case of a Class 1 token the AuthenticationResult status shall indicate Authentic when both of the following conditions are met:

        在1类令牌的情况下，当满足以下两个条件时，AuthenticationResult状态应表明真实： 

• the CRC checksum in the token has the same value as that calculated from the data elements in the token;

• 令牌中的CRC校验和与从令牌中的数据元素计算出的值相同；

• The MfrCode value in the token is the same as the MfrCode as defined in 6.2.3.

• 令牌中的MfrCode值与6.2.3中定义的MfrCode相同。

If any of the above conditions are not met, then the AuthenticationResult status shall indicate CRCError, or MfrCodeError, or both.

        如果上述任何一个条件都不满足，那么AuthenticationResult状态将显示CRCError或MfrCodeError，或两者都显示。

If the token cannot be authenticated, it shall be rejected in accordance with the requirements given in 8.2 and 8.3.

        如果该令牌无法通过认证，则根据8.2和8.3的要求拒绝该令牌。