Cryptographic security

• Informally, “cryptographic security” describes the type of resistance a given algorithm has against attempts to decode messages encrypted by it
  • provable security: a proof must exist for the algorithm which shows that the underlying difficult problem has no “back doors”; in other words, an attacker has no choice but to solve the problem directly in order to break the security
    • provable security doesn’t rely on simple obfuscation tactics that reduce the chances that a cipher will be cracked
  • information-theoretic security: security that doesn’t rely on the limitations of current computing technology; heavily related to “information theory”
    • security of information-theoretic secure algorithms will not break down with the advent of new technologies, such as quantum computing
    • a key example is the one-time pad ↗ algorithm (OTP)