这种加密有多安全？ [关闭]

Question

我有一个想法，用 python 的伪随机生成器生成的字节加密字符串，本质上创建一个一次性垫，这应该是安全的，问题是与随机生成器的播种有关以创建垫.

假设你不知道seed_key，随机生成器的种子冲突的可能性有多大？

#!/usr/bin/env python3

### IMPORTS ###
import random
from base91 import encode
from os import urandom

### CLASS DEFINITITON ###
class SeedPad:

    """ Encrypts a string with a one time pad generated by the pseudo random generator using a seed """

    def __init__(self, plain_text=None, cipher_text=None, seed_key=None):
        self.__plain_text = plain_text
        self.__cipher_text = cipher_text
        self.__seed_key = seed_key

    ### PROPERTY GETTERS ###
    @property
    def plain_text(self):
        return self.__plain_text

    @property
    def cipher_text(self):
        return self.__cipher_text

    @property
    def seed_key(self):
        return self.__seed_key

    ### PROPERTY SETTERS ###
    @plain_text.setter
    def plain_text(self, plain_text):
        self.__plain_text = plain_text

    @cipher_text.setter
    def cipher_text(self, cipher_text):
        self.__cipher_text = cipher_text
    
    @seed_key.setter
    def seed_key(self, seed_key):
        self.__seed_key = seed_key

    ### METHODS ###
    def encrypt(self):

        """ 
        takes a plain text string and returns a cipher_text as a hex string

        seed_key and plain_text must be set to use this method
        """

        if self.__plain_text is None:
            raise ValueError("plain_text is not set.")

        if self.__seed_key is None:
            self.__keygen()

        if type(self.__plain_text) != bytes:
            self.__plain_text = self.__plain_text.encode()

        random.seed(self.__seed_key)

        self.__cipher_text = ""

        for i in self.__plain_text:
            self.__cipher_text += f"{i ^ random.randint(0,255):02x}"

        return self.__cipher_text

    def decrypt(self):
        if self.__cipher_text is None:
            raise ValueError("cipher_text is not set.")

        if self.__seed_key is None:
            raise ValueError("seed_key is not set.")

        random.seed(self.__seed_key)

        # Convert hex string to bytes
        cipher_bytes = bytes.fromhex(self.cipher_text)


        self.__plain_text = ""

        for byte in cipher_bytes:
            self.__plain_text += chr(byte ^ random.randint(0, 255))

        return self.__plain_text

    def __keygen(self):
        self.__seed_key = encode(urandom(16))
        print("Random seed: ", self.__seed_key)


if __name__ == "__main__":
    
    from flag import flag, secret_key
    
    crypter = SeedPad(plain_text=flag, seed_key=secret_key)
    print(crypter.encrypt())

Answer 1

我相信您需要知道的一切都在 Random 类的文档中：

警告此模块的伪随机生成器不应用于安全目的。有关安全或加密用途，请参阅秘密模块。

还有：

Python 使用 Mersenne Twister 作为核心生成器。 . . .但是，由于是完全确定性的，它并不适合所有用途，并且完全不适合加密用途。