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Update README.MD

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Bill Buchanan
2021-02-25 18:17:48 +00:00
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parent cfe025e0b4
commit 514c0e36ba
1 changed files with 22 additions and 26 deletions
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unit05_key_exchange/lab/README.MD
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@@ -178,26 +178,23 @@ What happens to this sequence if we use g=3?
We can determine the values of g which will work for a given prime number with the following:
```python
import sys
import random
p=11
def getG(p):
for x in range (1,p):
rand = x
exp=1
next = rand % p
rand = x
exp=1
next = rand % p
while (next <> 1 ):
next = (next*rand) % p
exp = exp+1
while (next != 1 ):
next = (next*rand) % p
exp = exp+1
if (exp==p-1):
print (rand)
if (exp==p-1):
print rand
print getG(p)
print (getG(p))
```
Run the program and determine the possible g values for these prime numbers:
@@ -218,7 +215,6 @@ On the Internet, find a large prime number, and determine the values of g that a
We can write a Python program to implement this key exchange. Enter and run the following program:
```python
import random
import base64
import hashlib
import sys
@@ -232,25 +228,25 @@ b=random.randint(10,20)
A = (g**a) % p
B = (g**b) % p
print 'g: ',g,' (a shared value), n: ',p, ' (a prime number)'
print ('g: ',g,' (a shared value), n: ',p, ' (a prime number)')
print '\nAlice calculates:'
print 'a (Alice random): ',a
print 'Alice value (A): ',A,' (g^a) mod p'
print ('\nAlice calculates:')
print ('a (Alice random): ',a)
print ('Alice value (A): ',A,' (g^a) mod p')
print '\nBob calculates:'
print 'b (Bob random): ',b
print 'Bob value (B): ',B,' (g^b) mod p'
print ('\nBob calculates:')
print ('b (Bob random): ',b)
print ('Bob value (B): ',B,' (g^b) mod p')
print '\nAlice calculates:'
print ('\nAlice calculates:')
keyA=(B**a) % p
print 'Key: ',keyA,' (B^a) mod p'
print 'Key: ',hashlib.sha256(str(keyA)).hexdigest()
print ('Key: ',keyA,' (B^a) mod p')
print ('Key: ',hashlib.sha256(str(keyA).encode()).hexdigest())
print '\nBob calculates:'
print ('\nBob calculates:')
keyB=(A**b) % p
print 'Key: ',keyB,' (A^b) mod p'
print 'Key: ',hashlib.sha256(str(keyB)).hexdigest()
print ('Key: ',keyB,' (A^b) mod p')
print ('Key: ',hashlib.sha256(str(keyB).encode()).hexdigest())
```
Pick three different values for g and p, and make sure that the Diffie Hellman key exchange works.