Operation Manual

207 Copyright © Acronis International GmbH, 2002-2012
The window has the following legend: The first column of the list contains the type of operation on a
disk (there are just two: to write a symbol to disk, "writing"; and to verify written, "verification"); the
second column contains the pattern of data to be written to disk.
The pattern to be written is always a hexadecimal value, for example, a value of this kind: 0x00,
0xAA, or 0xCD, etc. These values are 1 byte long, but they may be up to 512 bytes long. Except for
such values, you may enter a random hexadecimal value of any length (up to 512 bytes). Your
algorithm may also include one more value for writing that is designated as the «complementary
value» – the value that is complementary to the one written to disk during the previous pass.
If the binary value is represented by the 10001010 (0x8A) sequence, then the complementary binary value will
be represented by the 01110101 (0x75) sequence.
The Algorithm definition window offers you the template for the algorithm only. You should define
exactly what the software should write to disk to destroy the confidential data according to your
algorithm.
To do this, click your mouse on the line representing pass #1 and click Edit.
Wiping pass adjustment
The Wiping Pass Adjustment window allows you to define the pattern to be written to disk
(hexadecimal value).
This is what the window control elements mean: You may enter any hexadecimal value into the field
under the Write pattern switch to write it to a hard disk during any pass (during the first pass in this
case).
By setting the switch to Write a random number position, you will first select to write a random
value to disk, and specify the length of the random value in bytes in the field below.
The U.S. standard provides the writing of random values to each byte of each disk sector during the
first pass, so set the switch to Write a random number position and enter 1 into the field.
Click the OK button to continue.
You will be taken to the algorithm definition window again and will see that the former record (write
– 00) was replaced by write – random, 1 byte.
To define the next pass, click the Add button.
You will see the already-familiar window, but this time there will be more switch positions available:
two additional positions will be available for selection:
 Write complementary to previous pass pattern: As during the second pass of the U.S. standard,
each disk sector is filled with hexadecimal values that are complementary to those written during
the previous pass. Therefore you should set the switch to the Write complementary to previous
pass pattern position and click the OK button.
You will be taken to the algorithm definition window again. In this window, the second record
looks like this: write – complementary to previous step pattern.
 Verify
Following the U.S. data destruction standard specification, define third and fourth data overwriting
passes.