Tagged Questions
2
votes
1answer
87 views
Computing RSA Algorithm
Modulus $N=247$; encryption exponent $r=7$
Encrypt $100$; Decrypt $120$.
$Solution:$ Encryption of $100$ is $35$. Decryption exponent of is $31$. Decryption of $120$ is $42$.
For a discrete math ...
0
votes
1answer
23 views
Explanation on step $\rho$ of the SHA-3 algorithm
I'm working on implementing SHA-3 in a PIC microcontroller.
In the block permutation, I don't quite understand step $\rho$:
Bitwise rotate each of the 25 words by a different triangular number 0, ...
0
votes
0answers
44 views
How would I create a birthday attack? (Hash Functions)
I'm trying to create an birthday attack, but I can't seem to get through it as I've never done it before. The basis: We have $E_K$, an encryption function, which has $N$ possible keys $K$, $N$ ...
8
votes
2answers
169 views
Who is the oldest? (in a non-revealing way)
How can a group of people figure out who is the oldest, without revealing any other information?
Revealing all the ages to a trusted third party is not allowed. Preferably I'm looking for solutions ...
4
votes
1answer
78 views
Does the difficulty of discrete logarithm depend on the difficulty of integer factorization?
The security of many (most? all?) public-key cryptography systems are based on the difficulty of the discrete logarithm or integer factorization. Are these two problems related at all?
With the ...
1
vote
0answers
34 views
Algorithms for Performing Large Integer Matrix Operations w/ Numerical Stability
I'm looking for a library that performs matrix operations on large sparse matrices w/o sacrificing numerical stability. Matrices will be 1000+ by 1000+ and values of the matrix will be between 0 and ...
0
votes
0answers
56 views
PrimeFactorUsingSpreadsheet-Positive integer maximum of 15 digits (from 1 to 999,999,999,999,999)
I need your help or suggestion to my project "Prime Factor By Saccuan's Lab"
Prime Factor Using Spreadsheet-Positive integer maximum of 15 digits (from 1 to 999,999,999,999,999) and if you can to ...
4
votes
1answer
85 views
Are there any secure ciphers you can use without a computer?
I have some kids that like encryption schemes such as the Caesar cipher and the Vigenère cipher. I would like to teach them something that's not easily breakable by todays maths and computers, but I ...
12
votes
3answers
273 views
Can we compare two secret numbers?
If you and I each have a secret number, is there a way we can find out whose is larger without either of us revealing our secret number?
Clearly a trusted third party could do the job, but I was ...
1
vote
1answer
100 views
How to randomly sort a sequence efficiently and simply?
Let me ask whether my instant simple algorithm has serious flaws ,for cryptography use, or not. Which is supposed to randomly change the order on a given sequence S[1..n] of the length n.
Assume I ...
1
vote
1answer
85 views
RSA calculations
I can not find a solution to the following problem.
The problem is:
We have an algorithm A for a decision problem that answers yes or no and for every input it gives the right answer with ...
0
votes
3answers
140 views
confusing in SEAL (Software-Optimized Encryption Algorithm) mathematic notation
I'm developing an encryption software based on SEAL algorihm for my research. I found the paper in here
My Question is what is the meaning of
$$
H_{i \operatorname{mod} 5}^i
$$
in page 5?
...
0
votes
1answer
388 views
Questions about cracking playfair using a 'shotgun climbing hill' method
I see this page before.
Cracking Playfair code
And I download the C file in it.However,I am still confused about the code.
How to evaluate a solution?
What does this mean?
...
1
vote
2answers
282 views
Running 'Encrypted Code' on a Computer
Alice released a new version of her software for removing red-eye from pictures. However, she wants to protect her secret algorithm from disassemblers and such while still letting her customers remove ...
3
votes
3answers
399 views
Encrypting algorithm
I know there are some encrypting algorithm that once the text (the message) is encrypted there is no way to decrypt it.
I can think one way of doing this: using as encryption key the current date at ...
