{
  "id": 19154473,
  "title": "Horible public key tricks",
  "url": "https://urgent.news/2026/11/09/horible-public-key-tricks",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-11-09T12:55:11.000Z",
  "source": {
    "name": "Lobsters",
    "slug": "lobsters",
    "url": "https://maurycyz.com/projects/badcert/"
  },
  "original_language": "en",
  "account": "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).\n\nThe 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.",
  "summary": null,
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}