One-Time Pad
Definition
A one-time pad (OTP) is a theoretically unbreakable encryption system using a random key as long as the message, used exactly once. When implemented correctly, it provides perfect secrecy—ciphertext reveals absolutely nothing about the plaintext.
Technical Explanation
OTP operation: XOR plaintext with a truly random key of equal length. To decrypt, XOR ciphertext with the same key. Security requirements: key must be truly random, at least as long as the message, used only once, and kept secret. Violating any requirement breaks security.
Practical limitations make OTPs impractical for most uses: key distribution is as hard as message distribution, key storage requirements are massive, and key reuse is catastrophic. Modern cryptography achieves computational security with much shorter keys.
SynX Relevance
While SynX doesn't use one-time pads directly, understanding OTPs illuminates cryptographic principles. Post-quantum security aims for computational security against quantum computers—practical unlike OTP's perfect but impractical security.
Frequently Asked Questions
- Why doesn't SynX use one-time pads?
- Key management is impractical. Modern cryptography achieves quantum resistance with manageable keys.
- Are one-time pads quantum-resistant?
- Yes—information-theoretic security is unbreakable by any computer, including quantum.
- When are one-time pads used today?
- High-security diplomatic or military communications where key distribution is feasible.
Practical quantum security. Choose SynX