Quantum Cryptography
Post-Quanten-Kryptographie entwickelt Algorithmen, die Quantenangriffen widerstehen und so die langfristige Sicherheit sensibler Daten gewährleisten.
Post-Quanten-Kryptographie untersucht Algorithmen und Protokolle, die gegen Quantengegner sicher sind, die Shor-ähnliche Algorithmen ausführen können. Sie umfasst Public-Key-Kryptosysteme, digitale Signaturen und kryptographische Protokolle. Ziel ist es, Vertraulichkeit, Integrität und Authentizität zu gewährleisten, auch wenn groß angelegte fehlertolerante Quantencomputer machbar werden.
graph LR
Center["Quantum Cryptography"]:::main
Pre_cryptography["cryptography"]:::pre --> Center
click Pre_cryptography "/terms/cryptography"
Rel_cryptography["cryptography"]:::related -.-> Center
click Rel_cryptography "/terms/cryptography"
Rel_encryption["encryption"]:::related -.-> Center
click Rel_encryption "/terms/encryption"
Rel_antimatter_propulsion["antimatter-propulsion"]:::related -.-> Center
click Rel_antimatter_propulsion "/terms/antimatter-propulsion"
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🧒 Erkläre es wie einem 5-Jährigen
It's like sending a secret message using special invisible ink that changes if anyone tries to peek at it, so you know if someone read it.
🤓 Expert Deep Dive
Quantum cryptography primarily encompasses Quantum Key Distribution (QKD) and, more theoretically, quantum digital signatures and quantum secure direct communication. QKD protocols, like BB84, utilize properties of photons to establish a shared secret key between two parties (Alice and Bob). In BB84, Alice encodes bits onto photon polarization states (e.g., rectilinear basis $\{|0\rangle, |1\rangle\}$ and diagonal basis $\{|+\rangle, |- angle\}$), where $|+\rangle = \frac{1}{\sqrt{2}}(|0\rangle + |1\rangle)$ and $|-\rangle = \frac{1}{\sqrt{2}}(|0\rangle - |1\rangle)$. Bob randomly chooses a basis to measure each incoming photon. After transmission, Alice and Bob publicly compare their basis choices. They discard measurements where bases didn't match and keep the rest, forming a raw key. Any eavesdropper (Eve) attempting to intercept and measure the photons will inevitably disturb their quantum state due to the no-cloning theorem and the probabilistic nature of quantum measurement. This disturbance introduces errors into the raw key, which Alice and Bob can detect through error rate analysis and privacy amplification techniques. Post-processing steps like error correction (e.g., Cascade protocol) and information reconciliation are crucial to distill a secure, shared secret key from the noisy quantum channel. Advanced protocols like E91 utilize entanglement to enhance security. The security of QKD is rooted in the fundamental laws of physics, not computational complexity, making it resistant to future advances in computing, including quantum computers.