6.5.2.3.5 DCTK: DecoderCommonTransferKey
DCTK values are used to support payment meters that use erasable magnetic card token carriers (i.e. TCT value = 01 ) and that are allocated to common SupplyGroups. A payment meter that has been allocated to a common SupplyGroup at the time of manufacture or repair can be loaded with the DCTK value that corresponds to the common SupplyGroup and that has been encrypted under a parent DITK. Subsequently, at the time of installation or operation, a payment meter that has to be re-allocated to another common SupplyGroup can be loaded with the corresponding DCTK value that has been encrypted under a parent DCTK.
DCTK值用于支持使用可擦除磁卡令牌载体的付费仪表（即TCT值= 01），并分配给公共供应组。在制造或维修时已分配给公共供应组的付费仪表可以装载对应于公共供应组的DCTK值，并且该值已在父DITK下加密。随后，在安装或操作时，必须重新分配给另一个公共供应组的付费仪表可以加载相应的DCTK值，该值已在父DCTK下加密。
A DCTK shall only be used with payment meters that use erasable magnetic card token carriers (TCT value = 01 ) and shall only be accepted by such payment meters. Payment meters with any other token carrier types (TCT value > 01 ) shall reject tokens encrypted under DCTK values.
DCTK只能与使用可擦除磁卡令牌载体（TCT值= 01）的付费仪表一起使用，且只能由该付费仪表接受。任何其他令牌载体类型的付费仪表（TCT值> 01）应拒绝根据DCTK值加密的令牌。
POS encryption devices shall not encrypt tokens using DCTK values other than for erasable magnetic card token carriers (TCT value = 01 ).
POS加密设备不得使用DCTK值加密令牌，可擦除磁卡令牌载体除外（TCT值= 01）。
A DCTK is a secret value, and shall not be accepted by a payment meter as a plaintext value. A payment meter shall only load a DCTK if it has been encrypted under the parent DecoderKey present in the DecoderKeyRegister. DCTK values are the property of the respective utility and are managed within the KeyManagementSystem.
DCTK是一个秘密值，不能作为明文值被付费仪表接受。如果DCTK已经在DecoderKeyRegister中存在的父DecoderKey下加密，付费仪表将只加载DCTK。DCTK值是相应实用程序的属性，由keymanagement系统管理。
A purchased or repaired payment meter with an erasable magnetic card token carrier (TCT value = 01 ) that leaves the manufacturer's premises may contain a DCTK value supplied by the KMC in the DecoderKeyRegister.
从制造商处购买或修复的带有可擦除磁卡令牌载体（TCT值= 01）的付费仪表可能包含由KMC在DecoderKeyRegister中提供的DCTK值。
A DCTK shall only be used for the following key management functions:
• as the parent key for another DCTK; in other words, to encrypt another DCTK for the purpose of introducing it into the DecoderKeyRegister;
• as the parent key for a DDTK; and
• as the parent key for a DUTK.
DCTK只能用于以下关键管理功能：
- 作为另一个DCTK的父键；换句话说，加密另一个DCTK，以便将其引入DecoderKeyRegister；
- 作为DDTK的父键；和
- 作为DUTK的父键。
The above functions may be performed via the key change token set, or via a manufacturer’s proprietary loading mechanism that utilizes the key change token set. A DCTK shall not be used to decrypt a DITK for the purpose of introducing it into the DecoderKeyRegister.Similarly a DCTK shall not be used to encrypt a DITK for the purpose of transferring it to the payment meter in the form of a token.
上述功能可以通过密钥更改令牌集执行，也可以通过制造商专有的利用密钥更改令牌集的加载机制执行。DCTK不得用于解密DITK以将其引入DecoderKeyRegister。类似地，DCTK不得用于加密DITK，以便以令牌的形式将其转移到付费表。
A DCTK can also be used to encrypt or decrypt other meter-specific management functions. It can be used to encrypt or decrypt a STS credit transfer function; in other words, a valid TransferCredit token can be encrypted or decrypted and applied by a payment meter that contains a DCTK in its DKR and that uses a magnetic card token carrier (TCT value = 01 ).
DCTK还可以用于加密或解密其他表计特定的管理功能。它可用于加密或解密STS信用传递函数；换句话说，有效的TransferCredit令牌可以被加密或解密，并由在其DKR中包含DCTK并使用磁卡令牌载体的付费表应用（TCT值= 01）。