凯撒加密—加密算法
在密码学中,恺撒密码是一种最简单且最广为人知的加密技术。它是一种替换加密的技术,
明文中的所有字母都在字母表上向后(或向前)按照一个固定数目进行偏移后被替换成密文。
import string
# abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
# defghijklmnopqrstuvwxyzabc DEFGHIJKLMNOPQRSTUVWXYZABC
# 凯撒加密---加密算法的实现
def kaisacrypt(text='hello', k=3):
# 对原有小写字母向右移动k位
lower = string.ascii_lowercase[k:] + string.ascii_lowercase[:k]
upper = string.ascii_uppercase[k:] + string.ascii_uppercase[:k]
# 用于创建字符串映射的转换表'hello'
table = str.maketrans(string.ascii_letters, lower+upper)
# 根据转换表去转换对应的字符
return text.translate(table)
def check(text):
"""
思路:
测试文本中是否存在至少两个最常见的英文单词, 如果有, 则代表破解成功.
"""
mostCommonWords = ('the', 'is', 'to', 'not', 'have', 'than', 'for', 'ok', 'and' )
return len([1 for word in mostCommonWords if word in text])>2
# 暴力破解
def bruteForce(text):
for i in range(26):
# 1,2,3,4,5
t = kaisacrypt(text, -i)
if check(t):
print(i)
print(t)
break
print(kaisacrypt())
import string
# abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
# defghijklmnopqrstuvwxyzabc DEFGHIJKLMNOPQRSTUVWXYZABC
# 凯撒加密---加密算法的实现
def kaisacrypt(text='hello', k=3):
# 对原有小写字母向右移动k位
lower = string.ascii_lowercase[k:] + string.ascii_lowercase[:k]
upper = string.ascii_uppercase[k:] + string.ascii_uppercase[:k]
# 用于创建字符串映射的转换表'hello'
table = str.maketrans(string.ascii_letters, lower+upper)
# 根据转换表去转换对应的字符
return text.translate(table)
def check(text):
"""
思路:
测试文本中是否存在至少两个最常见的英文单词, 如果有, 则代表破解成功.
"""
mostCommonWords = ('the', 'is', 'to', 'not', 'have', 'than', 'for', 'ok', 'and' )
return len([1 for word in mostCommonWords if word in text])>2
# 暴力破解
def bruteForce(text):
for i in range(26):
# 1,2,3,4,5
t = kaisacrypt(text, -i)
if check(t):
print(i)
print(t)
break
print(kaisacrypt())
text = "If not to the sun for smiling, warm is still in the sun there, but wewill laugh more confident calm;"
cryptStr = kaisacrypt(text=text, k=18)
print(cryptStr)
bruteForce(cryptStr)