Question

create a unique cryptography program with a unique or modified hash functions.

Answer 1

This is an encryption example of PyCrypto. An example of this is the Paramiko SSH module for python, which uses PyCrypto as a dependency to encrypt information. PyCrypto is very simple, yet extremely powerful and useful for encryption within the Python programming language. Knowledge of the basics of encryption is also very useful. Run this program in Python 2.7 version but in 3.0 or higher version.

from Crypto.Cipher import AES
#base64 is used for encoding. dont confuse encoding with encryption#
#encryption is used for disguising data
#encoding is used for putting data in a specific format
import base64
# os is for urandom, which is an accepted producer of randomness that
# is suitable for cryptology.
import os
def encryption(privateInfo):
        #32 bytes = 256 bits
        #16 = 128 bits
        # the block size for cipher obj, can be 16 24 or 32. 16 matches 128 bit.
        BLOCK_SIZE = 16
        # the character used for padding
        # used to ensure that your value is always a multiple of BLOCK_SIZE
        PADDING = '{'
        # function to pad the functions. Lambda
        # is used for abstraction of functions.
        # basically, its a function, and you define it, followed by the param
        # followed by a colon,
        # ex = lambda x: x+5
        pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * PADDING
        # encrypt with AES, encode with base64
        EncodeAES = lambda c, s: base64.b64encode(c.encrypt(pad(s)))
        # generate a randomized secret key with urandom
        secret = os.urandom(BLOCK_SIZE)
        print 'encryption key:',secret
        # creates the cipher obj using the key
        cipher = AES.new(secret)
        # encodes you private info!
        encoded = EncodeAES(cipher, privateInfo)
        print 'Encrypted string:', encoded

Decryption Example:

from Crypto.Cipher import AES
import base64
import os
def decryption(encryptedString):
        PADDING = '{'
        DecodeAES = lambda c, e: c.decrypt(base64.b64decode(e)).rstrip(PADDING)
        #Key is FROM the printout of 'secret' in encryption
        #below is the encryption.
        encryption = encryptedString
        key = ''
        cipher = AES.new(key)
        decoded = DecodeAES(cipher, encryption)
        print decoded

Note:

• You must run on Python 2.7.
• You need to download the modules to run the program.
• I have given the program for encryption and decryption also.

Hope you understand, Thank You!