ATopSoft FileCake document -- File shredder

In search file result, select the files you want to wipe out, the select 'Wipe' in the context menu, then a 'Wipe files' dialog box will pop up.
Wipe is an advanced security tool that allows you to remove sensitive data completely from your hard disk by overwriting it several times with carefully selected patterns.

Why do you need file shredder?
Because normal file deletion is insecure.
When you delete files in DOS or Windows, the operation system doesn't really delete the files. Instead of that, it only masks the files name with some special character, and the files content are still on the disk, so the files are not really deleted.
There are many disk utility can recover such 'deleted' files from your disk.
So simple deletion is not secure for sensitive data.
The 'Wipe' feature in FileCake can overwrite the files several times and the files can't be recovered.

Select a shredder algorithm
In the drop down combo box, you can select an algorithm to wipe.
The basic four kinds of algorithm are,
1. Simple shredder: Overwrite the file content with 0 for one time. This is very fast algorithm, but you should only choose it for not very important data. For sensitive data, choose US DoD 5220.22-M or Gutmann algorithm.
2. Express shredder: Overwrite the file content three times, one is with 0, then with random data, finally with all 1.
3. DoD 5220.22-M: Based on national "Industrial Security Program Operating Manual", NISPOM (also known as US DoD 5220.22-M), of United States Department of Defense. This algorithm is secure and fast enough for most area.
4. Gutmann algorithm: Based on Peter Gutmann's paper "Secure Deletion of Data from Magnetic and Solid-State Memory". This is one of the most secure algorithm and the files wiped by it are impossible recovered. But it's very slow, with 35 times overwriting.
The pseudorandom algorithm is ISAAC, guarantee at lease 2^40 period.
Input confirmation code
By default, the file wipe configuration dialog box requires you to type four letters confirmation code. The subsequent wiping will be valid only if your input is same with the red text displayed at the left. This is a very effective confirmation mechanism to avoid you mistakenly wipe useful files.
Though you can disable this function in configure, we strongly recommend you leave it enabled.
Delete file after wiping
If it's selected, the file that's being wiped will be deleted after wiping.
You should clear it only when you're testing your customized wiping algorithm.
The deletion method here used is more secure than you deleting it in Windows Explorer, so we recommend that you'd better never clear it unless you're testing your own wiping algorithm.
Delete empty directories
When any files are wiped and deleted, if the source directory is empy (has no any files in it), it will be deleted.
Customize the shredder algorithm
Beside above four algorithms, you can also define the wiping algorithm by yourself.
Just click button 'Customize', then select 'Add', 'Modify' or 'Delete' in the pop up menu.
1, Add: Add an algorithm. See below.
2, Modify: Modify an algorithm. See below.
3, Delete: Delete an algorithm.
You can only modify or delete customized algorithm, not the basic four algorithms.

Add/Modify customized algorithm:
After you click 'Add' or 'Modify', an 'Edit file wipe pattern' dialog box will pop up.

Name: Set a name for the pattern, it will be list in the algorithm selection combo box.

Operation: Set the operation for one action. The operation can be 'Overwrite', 'Xor', or 'Not'.
- Overwrite: Overwrite the file content with the given data.
- Xor: Xor the file content with the given data. Xor means: 1 xor 1 = 0, 1 xor 0 = 1, 0 xor 1 = 1, 0 xor 0 = 0.
- Not: Bit-wise complement of file content, the data is ignored. Not means: not 1 = 0, not 0 = 1.
Data:
Set the hexadecimal data that will be operated with the file content.
The data format should be like 1F, 9876ABCD, etc.
If the data should be random, input RR instead of any hex.