ISO/TR 19038:2005 provides the user with technical support and details for the safe and efficient implementation of the Triple Data Encryption Algorithm (TDEA) modes of operation for the enhanced cryptographic protection of digital data. The modes of operation described therein are specified for both enciphering and deciphering operations. The modes described in this Technical Report are implementations of the block cipher modes of operation specified in ISO/IEC 10116 using the Triple DEA algorithm (TDEA) specified in ISO/IEC 18033-3. The TDEA modes of operation may be used in both wholesale and retail financial applications. The use of ISO/TR 19038:2005 provides the basis for the interoperability of products and facilitates the development of application standards that use the TDEA modes of operation. This Technical Report is intended for use with other ISO standards using DEA.