t**o
发帖数: 31 | 1 问了很多人都不会做,这里牛人多,帮我看看吧?谢谢了.
Suppose that someone suggests the following way to confirm that the two of
you are both in possession of the same secret key. You create a random bit
string the length of the key, XOR it with the key, and send the result over
the channel. Your partner XORs the incoming block with they key (which
should be the same as your key) and sends it back. You check and what you
receive is your original random string, you have verified that your partner
has the same secret key, y | o**v
发帖数: 1662 | 2 XOR is just tooooo weak.
3DES/AES
over
partner
Is
about
【在 t**o 的大作中提到】
: 问了很多人都不会做,这里牛人多,帮我看看吧?谢谢了.
: Suppose that someone suggests the following way to confirm that the two of
: you are both in possession of the same secret key. You create a random bit
: string the length of the key, XOR it with the key, and send the result over
: the channel. Your partner XORs the incoming block with they key (which
: should be the same as your key) and sends it back. You check and what you
: receive is your original random string, you have verified that your partner
: has the same secret key, y
| t**o
发帖数: 31 | 3 版主大大,我这个学期才副修了网络课的,一点背景知识都没有.你能不能给我解释一下
这题怎么做啊?谢谢!
【在 o**v 的大作中提到】
: XOR is just tooooo weak.
: 3DES/AES
:
: over
: partner
: Is
: about
| c*a
发帖数: 806 | 4 wrong board? should be asking math?
a xor k = c
c xor k = a
k = a xor c?
【在 t**o 的大作中提到】
: 版主大大,我这个学期才副修了网络课的,一点背景知识都没有.你能不能给我解释一下
: 这题怎么做啊?谢谢!
| t**o
发帖数: 31 | 5 能不能详细点说说怎么解.
我知道用plaintext 11001100
+key stream 01101100
=cipertext 10100000
但是具体应用不会.请讲一下吧.谢谢!
【在 c*a 的大作中提到】
: wrong board? should be asking math?
: a xor k = c
: c xor k = a
: k = a xor c?
| k**q
发帖数: 135 | 6 知道是xor,知道plaintext和cipertext难道还算不出来
key?
【在 t**o 的大作中提到】
: 能不能详细点说说怎么解.
: 我知道用plaintext 11001100
: +key stream 01101100
: =cipertext 10100000
: 但是具体应用不会.请讲一下吧.谢谢!
| L******t
发帖数: 1985 | 7 You send a plaintext of your choice to receiver, who will send back you the
ciphertext. Then you got the key by plaintext XOR ciphertext.
Proof:
P xor K = C
P xor P xor K = K
==> K = P xor C
The weakness in the scheme is the encryption algorithm is reversible. And
the receiver cannot verify the authenticity of a sender.
【在 t**o 的大作中提到】
: 能不能详细点说说怎么解.
: 我知道用plaintext 11001100
: +key stream 01101100
: =cipertext 10100000
: 但是具体应用不会.请讲一下吧.谢谢!
| t**o
发帖数: 31 | 8 谢谢高手的解释,尤其是kkqq和lieheart的详细解释,我现在完全理解了.万分感谢!
over
partner
Is
about
【在 t**o 的大作中提到】
: 问了很多人都不会做,这里牛人多,帮我看看吧?谢谢了.
: Suppose that someone suggests the following way to confirm that the two of
: you are both in possession of the same secret key. You create a random bit
: string the length of the key, XOR it with the key, and send the result over
: the channel. Your partner XORs the incoming block with they key (which
: should be the same as your key) and sends it back. You check and what you
: receive is your original random string, you have verified that your partner
: has the same secret key, y
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