October 31, 2011

Yes Diffie-Hellman is secure

When it comes to the Diffie-Hellman algorithm, there seem to be many confusions from newbies in Cryptography as to whether an attacker could easily recompute the shared key by intercepting the prime numbers + public keys. While the answer is “no”, understanding why, requires an understanding the discrete logarithm problem. So here we go. ###Discrete Logarithm Problem### The discrete logarithm problem can be summarized as follow: Given $$a, b \in \mathbb{Z}/p\mathbb{Z} \wedge P$$ a prime, compute $$\log_b a$$ ... Read more