Coursera 上密码学公开课的 week1

admin 2025年1月10日16:39:33评论4 views字数 7915阅读26分23秒阅读模式

Coursera 上密码学公开课的 week1

Coursera 上 Dan Boneh 的密码学课程 week1

备课的 ppt, 懒得写 md 了。

小题

Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1

编程题

第一种方法

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from Crypto.Util import strxor
import re
import string
import pprint
#
c0 = ['32510ba9babebbbefd001547a810e67149caee11d945cd7fc81a05e9f85aac650e9052ba6a8cd8257bf14d13e6f0a803b54fde9e77472dbff89d71b57bddef121336cb85ccb8f3315f4b52e301d16e9f52f904',
'315c4eeaa8b5f8aaf9174145bf43e1784b8fa00dc71d885a804e5ee9fa40b16349c146fb778cdf2d3aff021dfff5b403b510d0d0455468aeb98622b137dae857553ccd8883a7bc37520e06e515d22c954eba5025b8cc57ee59418ce7dc6bc41556bdb36bbca3e8774301fbcaa3b83b220809560987815f65286764703de0f3d524400a19b159610b11ef3e',
'234c02ecbbfbafa3ed18510abd11fa724fcda2018a1a8342cf064bbde548b12b07df44ba7191d9606ef4081ffde5ad46a5069d9f7f543bedb9c861bf29c7e205132eda9382b0bc2c5c4b45f919cf3a9f1cb74151f6d551f4480c82b2cb24cc5b028aa76eb7b4ab24171ab3cdadb8356f',
'32510ba9a7b2bba9b8005d43a304b5714cc0bb0c8a34884dd91304b8ad40b62b07df44ba6e9d8a2368e51d04e0e7b207b70b9b8261112bacb6c866a232dfe257527dc29398f5f3251a0d47e503c66e935de81230b59b7afb5f41afa8d661cb',
'32510ba9aab2a8a4fd06414fb517b5605cc0aa0dc91a8908c2064ba8ad5ea06a029056f47a8ad3306ef5021eafe1ac01a81197847a5c68a1b78769a37bc8f4575432c198ccb4ef63590256e305cd3a9544ee4160ead45aef520489e7da7d835402bca670bda8eb775200b8dabbba246b130f040d8ec6447e2c767f3d30ed81ea2e4c1404e1315a1010e7229be6636aaa',
'3f561ba9adb4b6ebec54424ba317b564418fac0dd35f8c08d31a1fe9e24fe56808c213f17c81d9607cee021dafe1e001b21ade877a5e68bea88d61b93ac5ee0d562e8e9582f5ef375f0a4ae20ed86e935de81230b59b73fb4302cd95d770c65b40aaa065f2a5e33a5a0bb5dcaba43722130f042f8ec85b7c2070',
'32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd2061bbde24eb76a19d84aba34d8de287be84d07e7e9a30ee714979c7e1123a8bd9822a33ecaf512472e8e8f8db3f9635c1949e640c621854eba0d79eccf52ff111284b4cc61d11902aebc66f2b2e436434eacc0aba938220b084800c2ca4e693522643573b2c4ce35050b0cf774201f0fe52ac9f26d71b6cf61a711cc229f77ace7aa88a2f19983122b11be87a59c355d25f8e4',
'32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd90f1fa6ea5ba47b01c909ba7696cf606ef40c04afe1ac0aa8148dd066592ded9f8774b529c7ea125d298e8883f5e9305f4b44f915cb2bd05af51373fd9b4af511039fa2d96f83414aaaf261bda2e97b170fb5cce2a53e675c154c0d9681596934777e2275b381ce2e40582afe67650b13e72287ff2270abcf73bb028932836fbdecfecee0a3b894473c1bbeb6b4913a536ce4f9b13f1efff71ea313c8661dd9a4ce',
'315c4eeaa8b5f8bffd11155ea506b56041c6a00c8a08854dd21a4bbde54ce56801d943ba708b8a3574f40c00fff9e00fa1439fd0654327a3bfc860b92f89ee04132ecb9298f5fd2d5e4b45e40ecc3b9d59e9417df7c95bba410e9aa2ca24c5474da2f276baa3ac325918b2daada43d6712150441c2e04f6565517f317da9d3',
'271946f9bbb2aeadec111841a81abc300ecaa01bd8069d5cc91005e9fe4aad6e04d513e96d99de2569bc5e50eeeca709b50a8a987f4264edb6896fb537d0a716132ddc938fb0f836480e06ed0fcd6e9759f40462f9cf57f4564186a2c1778f1543efa270bda5e933421cbe88a4a52222190f471e9bd15f652b653b7071aec59a2705081ffe72651d08f822c9ed6d76e48b63ab15d0208573a7eef027',
'466d06ece998b7a2fb1d464fed2ced7641ddaa3cc31c9941cf110abbf409ed39598005b3399ccfafb61d0315fca0a314be138a9f32503bedac8067f03adbf3575c3b8edc9ba7f537530541ab0f9f3cd04ff50d66f1d559ba520e89a2cb2a83']

l = max([len(i) for i in c0])

m = [re.sub(r'.|\s','*',i.decode('hex')) for i in c0]
c = [(i+(l-len(i))*'0').decode('hex') for i in c0]

th = [[None] for ii in range(len(c))] #

for i in c:
alpha = []
rep = {}
for j in range(len(c)):
raw = strxor.strxor(i, c[j])

if i!=c[j]:
loc = [s.start() for s in re.finditer(r'[a-zA-Z]', raw)]
rep[j] = loc
alpha += loc

alpha = [k for k in set(alpha) if alpha.count(k) > 6]

for j in range(len(c)):
raw = strxor.strxor(i, c[j])

for k in alpha:

if k<len(m[j]):
if c[j]!=i:
if k in rep[j]:
#th[j]+=raw[k]#
#print th[j].count(raw[k])
#if th[j].count(raw[k])>6:#
m[j] = m[j][:k] + raw[k] + m[j][k+1:]
else:
m[j] = m[j][:k] + raw[k] + m[j][k+1:]

#----------------------------------------------------------------
for i in m:
print i.swapcase()
print '-'*50
#pprint.pprint(th)
'''
m[0]='The secret message is: when using a stream cipher, never use the key more than once'
key = strxor.strxor(m[0], c0[0].decode('hex'))
for i in c0:
print strxor.strxor(i.decode('hex')[:len(key)],key)

print '-'*50


#print strxor.strxor(strxor.strxor('attack at dawn','09e1c5f70a65ac519458e7e53f36'.decode('hex')),'attack at dusk').encode('hex')
'''

Coursera 上密码学公开课的 week1
Coursera 上密码学公开课的 week1

第二种方法

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# -*- coding: cp936 -*-
from Crypto.Util import strxor
import re,pprint

c0 = ['32510ba9babebbbefd001547a810e67149caee11d945cd7fc81a05e9f85aac650e9052ba6a8cd8257bf14d13e6f0a803b54fde9e77472dbff89d71b57bddef121336cb85ccb8f3315f4b52e301d16e9f52f904',
'315c4eeaa8b5f8aaf9174145bf43e1784b8fa00dc71d885a804e5ee9fa40b16349c146fb778cdf2d3aff021dfff5b403b510d0d0455468aeb98622b137dae857553ccd8883a7bc37520e06e515d22c954eba5025b8cc57ee59418ce7dc6bc41556bdb36bbca3e8774301fbcaa3b83b220809560987815f65286764703de0f3d524400a19b159610b11ef3e',
'234c02ecbbfbafa3ed18510abd11fa724fcda2018a1a8342cf064bbde548b12b07df44ba7191d9606ef4081ffde5ad46a5069d9f7f543bedb9c861bf29c7e205132eda9382b0bc2c5c4b45f919cf3a9f1cb74151f6d551f4480c82b2cb24cc5b028aa76eb7b4ab24171ab3cdadb8356f',
'32510ba9a7b2bba9b8005d43a304b5714cc0bb0c8a34884dd91304b8ad40b62b07df44ba6e9d8a2368e51d04e0e7b207b70b9b8261112bacb6c866a232dfe257527dc29398f5f3251a0d47e503c66e935de81230b59b7afb5f41afa8d661cb',
'32510ba9aab2a8a4fd06414fb517b5605cc0aa0dc91a8908c2064ba8ad5ea06a029056f47a8ad3306ef5021eafe1ac01a81197847a5c68a1b78769a37bc8f4575432c198ccb4ef63590256e305cd3a9544ee4160ead45aef520489e7da7d835402bca670bda8eb775200b8dabbba246b130f040d8ec6447e2c767f3d30ed81ea2e4c1404e1315a1010e7229be6636aaa',
'3f561ba9adb4b6ebec54424ba317b564418fac0dd35f8c08d31a1fe9e24fe56808c213f17c81d9607cee021dafe1e001b21ade877a5e68bea88d61b93ac5ee0d562e8e9582f5ef375f0a4ae20ed86e935de81230b59b73fb4302cd95d770c65b40aaa065f2a5e33a5a0bb5dcaba43722130f042f8ec85b7c2070',
'32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd2061bbde24eb76a19d84aba34d8de287be84d07e7e9a30ee714979c7e1123a8bd9822a33ecaf512472e8e8f8db3f9635c1949e640c621854eba0d79eccf52ff111284b4cc61d11902aebc66f2b2e436434eacc0aba938220b084800c2ca4e693522643573b2c4ce35050b0cf774201f0fe52ac9f26d71b6cf61a711cc229f77ace7aa88a2f19983122b11be87a59c355d25f8e4',
'32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd90f1fa6ea5ba47b01c909ba7696cf606ef40c04afe1ac0aa8148dd066592ded9f8774b529c7ea125d298e8883f5e9305f4b44f915cb2bd05af51373fd9b4af511039fa2d96f83414aaaf261bda2e97b170fb5cce2a53e675c154c0d9681596934777e2275b381ce2e40582afe67650b13e72287ff2270abcf73bb028932836fbdecfecee0a3b894473c1bbeb6b4913a536ce4f9b13f1efff71ea313c8661dd9a4ce',
'315c4eeaa8b5f8bffd11155ea506b56041c6a00c8a08854dd21a4bbde54ce56801d943ba708b8a3574f40c00fff9e00fa1439fd0654327a3bfc860b92f89ee04132ecb9298f5fd2d5e4b45e40ecc3b9d59e9417df7c95bba410e9aa2ca24c5474da2f276baa3ac325918b2daada43d6712150441c2e04f6565517f317da9d3',
'271946f9bbb2aeadec111841a81abc300ecaa01bd8069d5cc91005e9fe4aad6e04d513e96d99de2569bc5e50eeeca709b50a8a987f4264edb6896fb537d0a716132ddc938fb0f836480e06ed0fcd6e9759f40462f9cf57f4564186a2c1778f1543efa270bda5e933421cbe88a4a52222190f471e9bd15f652b653b7071aec59a2705081ffe72651d08f822c9ed6d76e48b63ab15d0208573a7eef027',
'466d06ece998b7a2fb1d464fed2ced7641ddaa3cc31c9941cf110abbf409ed39598005b3399ccfafb61d0315fca0a314be138a9f32503bedac8067f03adbf3575c3b8edc9ba7f537530541ab0f9f3cd04ff50d66f1d559ba520e89a2cb2a83']

l = min([len(i) for i in c0])#截成等长

C = ''.join([i[:l] for i in c0])

G = []
for z in set(re.findall(r'(.{2})',C)): #2 个一组
loc = [0]+[s.start() for s in re.finditer(z, C)]
G += [j-i for i,j in zip(loc,loc[1:])]


Keylen = 83
Key = ['*'] * Keylen

#14 个一组
Csplit = [re.findall(r'(.{2})',z) for z in re.findall(r'(.{'+str(Keylen*2)+'})',C)]

#转置
Transpose = map(list,[zip(*Csplit)])[0]

for i in range(Keylen):
m = 0
for k in range(255):
#统计字母, 标点个数
score = len(re.findall(r'[a-zA-Z ]',''.join([strxor.strxor(c.decode('hex'), chr(k)) for c in Transpose[i]])))
if m < score:
m = score
Key[i] = chr(k).encode('hex')

print 'Key:',''.join(Key)
Key = str(''.join(Key).decode('hex'))*1000
M = strxor.strxor(Key[:len(C.decode('hex'))],C.decode('hex'))
for i in re.findall(r'(.{'+str(Keylen)+'})',M):
print i

Coursera 上密码学公开课的 week1

- By:tr0y.wang

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  • 本文由 发表于 2025年1月10日16:39:33
  • 转载请保留本文链接(CN-SEC中文网:感谢原作者辛苦付出):
                   Coursera 上密码学公开课的 week1https://cn-sec.com/archives/3616220.html
                  免责声明:文章中涉及的程序(方法)可能带有攻击性,仅供安全研究与教学之用,读者将其信息做其他用途,由读者承担全部法律及连带责任,本站不承担任何法律及连带责任;如有问题可邮件联系(建议使用企业邮箱或有效邮箱,避免邮件被拦截,联系方式见首页),望知悉.

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