Diffie-Hellman Key Exchange Calculator

Calculate Diffie-Hellman key exchange parameters, shared secret, and security analysis.

Prime Modulus (p)

Generator (g)

Alice's Private Key (a)

Bob's Private Key (b)

Tab to move between fields

Alice's Public Key

Bob's Public Key

Shared Secret

Security Level

4.5 bits

Discrete Log Complexity4.8

How to Use This Calculator

Enter the prime modulus (p) and generator (g) values.
Set each party private key value.
Review the public keys and shared secret computed by the DH protocol.
Verify the shared secret matches on both sides to confirm the protocol works correctly.
Use group sizes of at least 2048 bits in production -- 768 and 1024-bit groups are deprecated.

How the result changes with Generator (g)

Generator (g)	Alice's Public Key	Bob's Public Key	Shared Secret
12	9	13	6
36	6	18	8
66	16	21	18
90	18	9	3

Shared Secret = (g^a)^b mod p = (g^b)^a mod p

Identify Input Parameters
4 parameters
Prime Modulus (p) = 23, Generator (g) = 5, Alice's Private Key (a) = 6, Bob's Private Key (b) = 15 = 4 input(s) provided
Calculate Alice's Public Key
Alice's Public Key
8 = 8
Calculate Bob's Public Key
Bob's Public Key
19 = 19
Calculate Shared Secret
Shared Secret
2 = 2
Calculate Discrete Log Complexity
Discrete Log Complexity
4.8 = 4.8

Engine last updated July 28, 2026. Checked against 3 independently-derived tests — how we verify calculators.

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