RSA加密算法Python实现

from random import randint
from datetime import datetime

"""判断是否是素数"""
def is_sushu(sushu):
    for i in range(2,sushu):
        if sushu % i == 0:
            return False
    return True

"""随机生成指定范围的大素数"""
def Create_Sushu():
    while True:
        sushu = randint(100,1000 )#下限越大，加密越安全，此处考虑计算时间，取值较小
        if is_sushu(sushu):
            return sushu

"""计算欧拉函数"""
def Oula(sushu1 , sushu2):
    return (sushu1-1)*(sushu2-1)

"""判断是否互质"""
def Is_Huzhi(int_min,int_max):
    for i in range(2,int_min+1):
        if int_min % i == 0 and int_max % i == 0:
            return False
    return True

"""计算公钥，直接计算编程较简单，此处考虑了计算效率的优化"""
def Creat_E(oula):
    top = oula
    while True:
        i = randint(2,top)
        for e in range(i,top):
            if Is_Huzhi(e,oula):
                return e     
        top = i    

"""计算私钥"""
def Compute_D(oula,e):
    k = 1
    while ( k*oula+1 )% e != 0:
        k+=1
    return int((k*oula+1)/e)

""" 将字符串转成ASCII """
def Transfer_To_Ascii(messages):
    result = []
    for message in messages:
        result.append(  ord(message) ) 
    return result

""" 将列表转化成字符串 """
def Transfer_To_String(string_list):
    string = ''.join(string_list)
    return string


if __name__ == "__main__":
    """ p、q为大素数 n=p*q oula = （p-1）* （q-1） e 为公钥 d 为私钥 """

    print("通信开始，正在计算公钥与私钥...")
    time_start = datetime.now()
    p = Create_Sushu()
    q = p
    while p ==q :
        q = Create_Sushu()
    n = p * q
    oula = Oula(p, q)
    e = Creat_E(oula)
    d = Compute_D(oula,e)
    time_end = datetime.now()
    print(f"计算完成，用时{str(time_end -time_start)}秒 ")
    print(f"公钥：n = {str(n)} , e = {str(e)}")
    print(f"私钥：n = {str(n)} , d = {str(d)}")
    #print('p='+str(p)+'\n'+'q='+str(q)+'\n'+'n='+str(n)+'\n'+'oula='+str(oula)+'\n'+'d='+str(d)+'\n')

    m = input('待加密信息：')
    m_list = Transfer_To_Ascii(m)

    print("正在加密...")
    c_list = []
    for m in m_list:
        c = m**e%n
        c_list.append(c)
    print(f"密文：{c_list}")

    print("正在解密...")
    decode_messages=[]
    for c in c_list:
        decode_message = c**d%n
        decode_messages.append(chr(decode_message))
    print(f"解密信息：{Transfer_To_String(decode_messages)}")