Eureka Encryption Library Help
Other Features


Expansion
Expansion regards the hiding of the encrypted data into a sea of data. Each encrypted character is followed by a random number of encrypted worthless characters. The number of padding change for each byte in a truly random fashion so attacking this data will yield far more difficulties in the attack than in a straight data encryption.

When you generate the cryptive files needed by the use of the EurGenBinaryKeys or EurGenTextKeys, a series of keys are generated for this purpose. Whenever you call one of the Expand routines, these keys are applied to the expansion.

You can expect the size of the encrypted files to be several times larger than the data file, so expect longer processing time for larger files.

Scrambling
Scrambling was included as an aid for disgusing an encrypted file even more. There are two kinds of scrambling; a ratio type and a random type.

Here's how the basic scramble process works. Each block will read a certain number of characters. That string of characters are reversed or mirrored and then written to another file, or rewritten to the existing file at that position.

The two calls are EurScrambleFile (ratio) and EurXScrambleFile (random). See the Procedures section for call structure and examples on calling them. For now, let us look at some considerations regarding the calls.

EurScrambleFile
The ratio style will use fixed record blocks (bytes) of data. You supply the number of blocks and the blocksize to process. You may need to use the LOF() function or other means to retrieve the filesize of the file you want to scramble so you will not request more bytes than the file contains.

Let us assume you have a file with 500 bytes. You could scramble it like the following:
5 Blocks, blocksize 100 (each 100 byte string will be reversed for the entire file)
10 Blocks, blocksize 50 (each 50 byte string will be reversed for the entire file)
25 Blocks, blocksize 10 (each 10 byte string will be reversed for twenty-five times)
Note that the third example will only scamble the first 250 bytes, leaving the remaining bytes unscrambled.

EurXScramble
The random style is far superior. A table will be generated based on the files created when you perform a EurGenBinaryKeys or EurGenTextKeys call. Each number in the table will determine the number of bytes to scramble within the file in sequence. This will continue for the entire file.

For an example, if the table generated produced the following numbers in the table 3,12,6,44 etc. then the following would occur:
03 - File position 01: first three bytes are mirrored.
12 - File position 04: next 12 bytes are mirrored.
06 - File position 16: next 6 bytes are mirrored.
44 - File position 22: next 44 bytes are mirrored.
and so on...

Back to Menu


Support and technical issues can be directed via eureka@datasecuritysolutions.com


Copyright © 1994-2000, 2002, 2003, 2005, 2007 Data Security Solutions, Inc. All rights reserved.