Sha256: de1a32bc763d3610664472c0f5561f8a41a2f4554c12f140d7720956d2c49a62
Contents?: true
Size: 1.27 KB
Versions: 183
Compression:
Stored size: 1.27 KB
Contents
# Diffie Hellman
Diffie-Hellman key exchange.
Alice and Bob use Diffie-Hellman key exchange to share secrets. They
start with prime numbers, pick private keys, generate and share public
keys, and then generate a shared secret key.
## Step 0
The test program supplies prime numbers p and g.
## Step 1
Alice picks a private key, a, greater than 1 and less than p. Bob does
the same to pick a private key b.
## Step 2
Alice calculates a public key A.
A = g**a mod p
Using the same p and g, Bob similarly calculates a public key B from his
private key b.
## Step 3
Alice and Bob exchange public keys. Alice calculates secret key s.
s = B**a mod p
Bob calculates
s = A**b mod p
The calculations produce the same result! Alice and Bob now share
secret s.
## Hints
For this exercise the following F# feature comes in handy:
- [BigInt](https://msdn.microsoft.com/en-us/visualfsharpdocs/conceptual/numerics.biginteger-structure-%5Bfsharp%5D)
## Source
Wikipedia, 1024 bit key from www.cryptopp.com/wiki. [http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange](http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange)
## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
Version data entries
183 entries across 183 versions & 1 rubygems