The second block of each message is the data. Although the data is shown in the illustration to be a single 512-bit block --in fact it is a NALU chunk for MPEG-2. The SHA-1 is computed against this block after NALU conversion to be H(SHA1(MessageData)). Since this is a DES message, there are only 8 7-bit block within the data. Using the Big-Endian bit ordering as the signature block has, the hash value of the second block is shown here as H(MessageBlock2).
Figure 35 shows the outbound message for a signed message (the inbound message is the same except that the S/MIME header parts are replaced with PKCS #7). The first block indicates that a signature is included in an attached file (.p7s) as described above.
RImage -ImageFile ImageFile.bff -TempDirectory TempDir -InputImageFile InputFile.bff > OutputFile.bff -SystemFunctionality SeparateProcess > -SystemFunctionalityContextSelect ToolSelection > -ApplicationName ApplicationName -UserName UserName > -ComplexClassificationType ComplexType > -DiscreteClassificationType DiscreteType -DataType DataType When you run a disk image recovery, the RImage program interacts with the disk image being analyzed by the Disk Imager program, the Disk Imager program creates a temporary image file (.bff in this example) that will be later reused as the output disk image file. See Figure 37. 7211a4ac4a