FRACTAL ENCRYPTION

Fractal encryption, as implemented by SummerSoft Labs, is a common-key encryption method, featuring:

- No size inflation,
- User selectable keys, and,
- Light weight and high speed.

First, an encryption key (K) is fractally encoded to make K'. K is the first q bytes of any file a user selects and considered to be an image of a square. Lavender_C supports up to 64-byte x 64-byte squares (q = 4,096). Our fractal encoding sheme is based on quadtree partitions.

   K => K'

=> indicates the fractal encryption process. Please note that this process is an irrevocable one; there is no way to rebuild K from K'. The size of K' is slightly lower than the original key (K).

Then K' is used to scramble the original file (OF) to be enciphered, genarating a corresponding enciphered file (EF).

   OF + K' = EF (eq. 1)

Namely,

   OF [O1, O2, ...................., On]
   +
   K' [K1, K2, ...., Kj]
   ||
   EF [E1, E2, ....................., En]

In this diagram, OF, K', and EF contain n, j, and n bytes, respectively. As shown, the size of OF and that of EF are the same. Lavender_C adds 8 bytes to the top of EF as a signature:

   EF [signature (8 bytes), E1, E2, ....................., En]

To decrypt EF, the same K is used to generate K'. Then,

    EF - K' = OF (eq. 2)

is performed. The signature is stripped out before this operation.

The addition (+) in eq. 1 and subtraction (-) in eq. 2 involve random-number scramble operations.

If you need further details of the operation, please contact us.