## What happens when xor inBlock chaining returns false?

What is the standard action for a blockchaining algorithm for two equal plain text blocks to be coded into two different ciphertext blocks?

## combinatory – XOR of rows and columns of magic 4×4 squares

An article by John Conway, Simon Norton and Alex Ryba, "The 880 Magic Spaces of Frenicle", in Jennifer Beineke and Jason Rosenhouse, ed., The Mathematics of Various Entertainment Topics, vol. 2, 2017, Chapter 5, reports the property "Nimm0" for magic 4×4 squares with numbers from 0 to 15, with also a sum constraint on the diagonals:
the bitwise exclusive OR (XOR) of all numbers in a row or column is always 0 (see also an example here). This can be verified with a comprehensive test of all 880 squares.
In note 1, they say that a conceptual proof was independently discovered by Friedrich Fitting and Oliviero Giordano Cassani.
However, I can not find the evidence on the web.
Anyone can share it here?
Or is he able to rediscover it?

## Discrete mathematics – Is it possible to determine if a given number is xor combination of some numbers?

I was given a number Y that is ($$a$$ xor $$b$$ xor $$c$$ xor $$d$$ xor $$e$$ ) some numbers ($$a$$,$$b$$,$$c$$,$$d$$,$$e$$) and another no X. Now, I have to determine if X is a combination xor of ($$a$$,$$b$$,$$c$$,$$d$$,$$e$$)

for example – ($$a$$ xor $$d$$), ($$b$$ xor $$c$$ xor $$e$$), ( $$a$$ xor $$e$$ )

What I know clearly is that let's say X = ($$b$$ xor $$d$$), Now if I xor X and Y I get
($$a$$ xor $$c$$ xor $$e$$), as ( $$b$$ xor $$b$$= 0) and if it was a number that was not a combination xor (let's say $$p$$ ) then I would have had ($$a$$ xor $$b$$ xor $$c$$ xor $$d$$ xor $$e$$ xor $$p$$)

How should I address this issue?

Posted on

## c ++ – Max XOR of two elements in a table

I was looking for an efficient algorithm to calculate the maximum xor possible of two numbers in a table …
I found two effective approaches which one uses try and an algorithm I found on LeetCode that promises results in O (nlog (U)) U is the number of bits in the elements of the Board. This algorithm works correctly. However, I have trouble understanding how it works.

Here is the code snippet

``````int findMaximumXOR (vector& nums) {
int test_max = 0;
int max = 0;
unordered_set s;
for (long long i = 30; i> = 0; - i) {
mask | = 1ll << i;

printf (" n" BYTE_TO_BINARY_PATTERN, BYTE_TO_BINARY (mask));

for (int num: nums) {
}

test_max = max | 1 << i;
for (int s_val: s) {
if (s.find (s_val ^ test_max)! = s.end ()) {
max = test_max;
Pause;
}
}
s.clear ();
}
back max;
}

``````

** The byte_to_binary is a macro defined by me to print the binary representation of a number

** I did not know if this type of question was better suited to StackOverflow or code review … it was not suitable for code review … just let me know.

Posted on Tags , , ,

## MySQL XOR produces incorrect results

Why the expression `conv (& # 39; 9000084e703720f9 & quot ;, 16,10) conv (& quot; 801A93A5A18A773F & quot ;, 16,10)` produces a wrong result?

In a step-by-step explanation:

``````SELECT conv (& # 39; 9000084e703720f9 & # 39 ;, 16, 10);
``````

Result: 10376302674444755193

``````SELECT conv (& # 39; 801A93A5A18A773F & # 39 ;, 16, 10);
``````

Result: 9230852725838346047

``````SELECT 10376302674444755193; 9230852725838346047;
``````

Result: 1160411291139790790

But by this request:

``````SELECT conv (& # 39; 9000084e703720f9 & # 39 ;, 16, 10) conv (& quot; 801A93A5A18A773F & # 39 ;, 16, 10)
``````

Result: 0

I do not understand why it returns zero?

## encryption – hash XOR SHA and Base64

What does this mean for XOR a SHA-256 hash (of an input string) with a Base64 value?
I'm attacking a scenario in which an input string and a base64 value is given and I have to produce an output string after doing this operation. If I understood correctly, a hash function produces an array of bytes and a base64 value can also provide me with an array of bytes (in C #, it is Convert. FromBase64String ()). Can these two be XORed and the result converted to a UTF8 string?

Does not UTF8 need the byte array to be in a specific format? I may miss something fundamental here.

## Cryptography – What are the options for encoding strings in addition to xor?

When you try to hide strings in a modern program, xor is probably the most common option. By this I mean the execution of each character of a string by a function that xorizes the character with a given number. This is popular because when "encrypted text" is xorated with the same number, it is restored to plain text.

I'd like to know about other math options that I have that can be used to encode a string that does not use xor operation. Are there other binary mathematical operators such as AND or OR that can be used instead of xor? How about shifting left, shift right, rotate, etc …? Can XOR be broken down into other atomic operations? Please give an example.

Posted on

## Implementation of the depth circuit 3 for XOR

In this set of notes, they claim that there is a size $$O (2 ^ { sqrt n})$$ depth-3 circuit (OR -AND -OR) that implements XOR.

I've tried a little to understand how to do this, but I have not been able to find such a construction. How do you do that?

## find the XOR between n and n

I have recently found this solution code of someone while I was unable to solve this problem.

``````                            import java.util. *;
import java.lang. *;
import java.io. *;

/ * The class name must be "Main" only if the class is public. * /
public class Codechef
{
public static void main (String[] args) throws java.lang.Exception
{
// your code goes herestatic int myXOR (int x, int y)

int l = 9;

int r = 12;

int x = (l | (l + 1)) & (~ l | ~ (l + 1));
for (int i = (l + 2); i <= r; i ++)
{
x = (x | i) & (~ x | ~ i);
}

if (x% 2 == 0)
{
System.out.println ("pair");
}
other
{
System.out.println ("odd");
}
}

// Driver code

}
``````

BUT I do not understand this specific logic below

``````int l = 9;

int r = 12;

int x = (l | (l + 1)) & (~ l | ~ (l + 1));
for (int i = (l + 2); i <= r; i ++)
{
x = (x | i) & (~ x | ~ i);
}
``````

Posted on Tags ,

## help me please understand this question about xor chains and hash sha-1

I have a problem to solve. But not sure to have it properly understood. I know how to find the XOR of 2 channels but I do not know what to choose for UTF8, is it ASCII? also what output format should I choose to run sha-1? I tried some combinations but all the answers turned out to be wrong. ``````XOR the following two UTF8 strings together: