Feal-ALL

This tool is the implementation of the FEAL NX / FEAL N and FEAL-4 encryption
Feal-NX is the latest version of FEAL encryption,supporting 128 bits key .
Feal-N is a similar version , restricte to 64 bits keys.
Feal-4 is similar to Feal-N with a small difference with the F-box & last xor at the end of the encypt function

• N is the number of rounds.

This tool is based on these papers :

• FEAL-NX SPECIFICATIONS
• The FEAL Cipher Family
• L'article de TheAmazingKing

(All the steps of the Feal NX code are detailed to understand the encryption with the paper next to it)

Example :

from FEAL.feal_nx import *
from FEAL.feal_n import *
from FEAL.feal_4 import *

msg = b'Hello This Is Vozec !'

engine1 = Feal_NX(key = b'ThisIsASecretKey',rounds = 32)
engine2 = Feal_N(key = b'Secpass!',rounds = 8)
engine3 = Feal_4(key = b'Secpass!')


print('\n## FEAL NX ##')
ct = engine1.encrypt(msg)
print('Cipher Text: %s'%ct)
pt = engine1.decrypt(ct)
print('Plain  Text: %s'%pt)



print('\n## FEAL N ##')
ct = engine2.encrypt(msg)
print('Cipher Text: %s'%ct)
pt = engine2.decrypt(ct)
print('Plain  Text: %s'%pt)



print('\n## FEAL 4 ##')
ct = engine3.encrypt(msg)
print('Cipher Text: %s'%ct)
pt = engine3.decrypt(ct)
print('Plain  Text: %s'%pt)

Result :

$ python3 example.py
## FEAL NX ##
Cipher Text: b'\x96\xb1\xfd\x97\xa3>g\x1c\x03\xe1\xb0\xb1\x1e\x0cC\x10\xd2y\xea,\xc5\xde\x12\xb5'
Plain  Text: b'Hello This Is Vozec !'

## FEAL N ##
Cipher Text: b'e\x7f\xdaJz\xe8\x1a\x85\xcb\xbb\xfd\xe7=\x84a\xfdf\xeb\xfe[@4\x08\xe5'
Plain  Text: b'Hello This Is Vozec !'

## FEAL 4 ##
Cipher Text: b'\xef\x01\xc5&(r\xb6H4\xed\xe4\xe9u\xf3\xaf\x03\xe0\xd3a\xdf\x14\x81\xe3\x9c'
Plain  Text: b'Hello This Is Vozec !'

Test :

All tests presented in the pdf for feal_nx & feal_n are performed in test.py