Muldersoft/SlunkCrypt
Muldersoft/SlunkCrypt
1
0
Fork 0
Code Releases 6 Activity

Updated README file.

Browse Source
This commit is contained in:
LoRd_MuldeR 2022-10-24 22:36:42 +02:00
parent 6f46d5ca20
commit 3fd5167809
Signed by: mulder
GPG Key ID: 2B5913365F57E03F
1 changed files with 14 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
README.md
View File

@ -201,7 +201,7 @@ Here are some examples on how to use the SlunkCrypt command-line application:
Encryption algorithm
====================
The SlunkCrypt algorithm is based on core concepts of the well-known [**Enigma**](https://en.wikipedia.org/wiki/Enigma_machine) machine but with numerous improvements, largely inspired by R. Anderson's [***“A Modern Rotor Machine”***](https://rdcu.be/cBo8y):
SlunkCrypt is based on concepts of the well-known [**Enigma**](https://en.wikipedia.org/wiki/Enigma_machine) machine, but with numerous "modern" improvements, largely inspired by [***“A Modern Rotor Machine”***](https://rdcu.be/cBo8y):
- The original Enigma machine had only *three* (or, in some models, *four*) rotors, plus a static "reflector" wheel. In SlunkCrypt, we uses **256** simulated rotors for an improved security. Furthermore, the original Enigma machine supported only 26 distinct symbols, i.e. the letters `A` to `Z`. In SlunkCrypt, we use **256** distinct symbols, i.e. the byte values `0x00` to `0xFF`, which allows the encryption (and decryption) of arbitrary streams of bytes, rather than just plain text. Of course, SlunkCrypt can encrypt (and decrypt) text files as well.
@ -213,6 +213,19 @@ The SlunkCrypt algorithm is based on core concepts of the well-known [**Enigma**
- SlunkCrypt does **not** currently implement the *plugboard* (“Steckerbrett”) of the original Enigma machine. That is because, even though the plugboard has a large key space, it is just a *fixed* substitution cipher that does *not* contribute much to the cryptographic strength of the Enigma machine. In fact, the plugboard could be "erased" by Welchman's [diagonal board](https://en.wikipedia.org/wiki/Bombe#Stecker_values).
Details
-------
This section explains some implementation details of the SlunkCrypt library:
* **DRBG:** The *deterministic random bit generator* (DRBG) employed by SlunkCrypt is called [*Xorwow*](https://en.wikipedia.org/wiki/Xorshift#xorwow), an enhanced variant of *Xorshift* , i.e. a form of *linear-feedback shift registers (LSFR)*.
* **Initialization (key schedule):** In the initialization phase, the *pseudo-random* internal wiring (i.e. permutation) is generated &ndash; separately for each of the 256 rotors. For this purpose, the initial state of the DRBG is set up in a way that depends on the given *passphrase*, a message-specific *nonce* as well as the current *rotor index*. More specifically, the initial state of the DRBG is derived from a combination of all input parameters, by applying a <u>large</u> number of iterations of the *FNV&#8209;1a 128-Bit* hash function. The permutation for the current rotor is then created by the ***Fisher&#8209;Yates*** shuffle algorithm, using the DRBG as its randomness source. This produces a distinct "randomized" internal rotor wiring for each message to be encrypted.
* **Message processing:** During the encryption or decryption process, the individual offsets (positions) of the first 8 rotors are controlled by a 64-Bit counter, whereas the offsets of the remaining 248 rotors are continuously "randomized" by the DRBG. The initial counter value as well as the initial state of the DRBG are set up in a way that depends on the given *passphrase* and a message-specific *nonce*. Also, after each symbol that was processed, the counter is incremented by one and new *pseudo-random* offsets (rotor positions) are drawn.
* **Checksum:** The message-length is padded to a multiple of 8 bytes and a 64-Bit [BLAKE2s](https://www.blake2.net/) hash is appended, *before* encryption. This "checksum" can be used to detect decryption errors.
Programming Interface (API)
===========================