6.5.2.3.4 DUTK: DecoderUniqueTransferKey
DUTK values are used to support payment meters allocated to a unique SupplyGroup. A payment meter that has been allocated to a unique SupplyGroup at the time of manufacture or repair can be loaded with its DUTK value that corresponds to the unique group and that has been encrypted under a parent DITK. Subsequently, at the time of installation or operation, a payment meter, which has to be re-allocated to another unique group can be loaded with the corresponding DUTK value, encrypted under a parent DUTK.
DUTK值用于支持分配给唯一SupplyGroup的付费表。在制造或维修时分配给唯一SupplyGroup的付费表可以加载其DUTK值，该值与唯一组相对应，并在父DITK下进行加密。随后，在安装或操作时，必须重新分配给另一个唯一组的付费表可以加载相应的DUTK值，并在父DUTK下加密。
A DUTK is a secret value, and shall not be accepted by a payment meter as a plaintext value. A payment meter shall only load a DUTK if it has been encrypted under the parent DecoderKey present in the DecoderKeyRegister. DUTK values are the property of the respective utility and are managed within the KeyManagementSystem.
DUTK是一个秘密值，不能作为明文值被付费表接受。如果DUTK已经在DecoderKeyRegister中存在的父DecoderKey下加密，付费表将只加载DUTK。DUTK值是各自实用程序的属性，由keymanagement系统管理。
A purchased or repaired payment meter that leaves the manufacturer's premises may contain a DUTK value supplied by the KMC in the DecoderKeyRegister.
从制造商处购买或修理的付费表可能包含由KMC在DecoderKeyRegister中提供的DUTK值。
A DUTK shall only be used for the following key management functions:
• as the parent key for another DUTK; in other words, to encrypt another DUTK for the purpose of introducing it into the DecoderKeyRegister; and
• as the parent key for a DDTK.
DUTK只能用于以下关键管理功能：
- 作为另一个DUTK的父键；换句话说，加密另一个DUTK，以便将它引入DecoderKeyRegister；和
- 作为DDTK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 DUTK shall not be used to decrypt a DITK or a DCTK for the purpose of loading it into the DecoderKeyRegister. Similarly a DUTK shall not be used to encrypt a DITK or a DCTK 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。DUTK不得用于解密DITK或DCTK以便将其加载到DecoderKeyRegister中。类似地，DUTK不得用于加密DITK或DCTK，以便以令牌的形式将其转移到付费表。
A DUTK 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 DUTK in its DKR.
DUTK还可以用于加密或解密其他meter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DUTK的付费表应用。