network profile
| bio | website | |
|---|---|---|
| location | ||
| age | ||
| visits | member for | 6 months |
| seen | Nov 1 '12 at 17:42 | |
| stats | profile views | 6 |
|
Nov 1 |
comment |
Distinguish messages I would like to compare the number of strings of length equal or less than $p(n)$ with the number of strings of length $p(n)+n$. Is this a good idea? |
|
Nov 1 |
revised |
Proving that a scheme is not IND-CPA-secure added 35 characters in body |
|
Nov 1 |
asked | Proving that a scheme is not IND-CPA-secure |
|
Oct 31 |
comment |
Distinguish messages I want to show that it is not secure when the messages are of different lengths. My thought was this: suppose that the encryption of a single bit cannot be longer than $p(n)$, what do we know about a message of lets say length $p(n)+n$? My idea was to let the adversary select $m_0 \in \{0,1\}$ and $m_1 \in \{0,1\}^{p(n)+n}$. |
|
Oct 31 |
comment |
Distinguish messages How do I know how big $l_1$ should be? And what is the chance of $m_0$ being encrypted in a ciphertext longer than $l_1$? |
|
Oct 31 |
awarded | Scholar |
|
Oct 31 |
accepted | Distinguish messages |
|
Oct 31 |
comment |
Distinguish messages Thank you. "Now, suppose you have the two messages $||m_0||=l_0$, $||m_1||=l_1$ and $l_0<<l_1$ (say $l_0=$1bit and $l_1$ is very large >10Gbits). If you receive a ciphertext shorter than $l_1$ you know that $m_1$ was encrypted." I guess you meant $m_0$ in this last sentence? |
|
Oct 30 |
awarded | Student |
|
Oct 30 |
asked | Distinguish messages |
|
Oct 30 |
awarded | Editor |
|
Oct 29 |
comment |
Modifications of CBC-MAC @Bob, I still don't understand it. What happens when the message is of length > 2^n? |
|
Oct 29 |
comment |
Modifications of CBC-MAC @bob, will you please explain 3? |
