Horible public key tricks

The article discusses a method to create a "vanity" SSL/TLS certificate by crafting a public key with a message embedded within it. This is achieved by selecting two large prime numbers, p and q, multiplying them to obtain a modulus (n), and modifying the bytes of n to include a desired message in the base64 encoding. However, this results in a weak private key since the private exponent (d) depends on knowing the prime factors (p and q).

The article highlights the risks of using SSL/TLS certificates, mentioning that certificates are issued over plaintext connections and are vulnerable to passive eavesdropping. The author suggests that using a vanity certificate can provide a simple solution to encrypt web traffic without the complexity of the ACME dance. The process involves generating a private key with a vanity public exponent of 65537, modifying the modulus value to incorporate a message, and then finding a corresponding private exponent.

The author also notes the challenges in aligning the message within the certificate and the need to renew the certificate periodically.