# Quantum Key-length Extension

@article{Jaeger2021QuantumKE, title={Quantum Key-length Extension}, author={Joseph Jaeger and Fang Song and Stefano Tessaro}, journal={ArXiv}, year={2021}, volume={abs/2105.01242} }

. Should quantum computers become available, they will reduce the eﬀective key length of basic secret-key primitives, such as blockciphers. To address this we will either need to use blockciphers with inherently longer keys or develop key-length extension techniques to amplify the security of a blockcipher to use longer keys. We consider the latter approach and revisit the FX and double encryption constructions. Classically, FX was proven to be a secure key-length extension technique, while…

## 5 Citations

### Beyond quadratic speedups in quantum attacks on symmetric schemes

- Computer Science, MathematicsIACR Cryptol. ePrint Arch.
- 2021

The first quantum key-recovery attack on a symmetric block cipher design, using classical queries only, is reported, with a more than quadratic time speedup compared to the best classical attack.

### Post-Quantum Security of the (Tweakable) FX Construction, and Applications

- Computer Science, Mathematics
- 2022

This work proves security of a tweakable version of the FX construction in the post-quantum setting, i.e., against a quantum attacker given only classical access to the secretly keyed construction while retaining quantum access to E.

### Post-Quantum Security of the Even-Mansour Cipher

- Computer Science, MathematicsIACR Cryptol. ePrint Arch.
- 2021

This work resolves the question as to whether the Even-Mansour cipher can still be proven secure in this natural, “post-quantum” setting, showing that any attack in that setting requires qE · q P + qP · q E ≈ 2.

### Quantum circuits with classical channels and the principle of deferred measurements

- Computer ScienceTheor. Comput. Sci.
- 2022

### Adaptive versus Static Multi-oracle Algorithms, and Quantum Security of a Split-key PRF

- Computer Science, MathematicsIACR Cryptol. ePrint Arch.
- 2022

A generic compiler is shown that the hash-based construction of Giacon et al. can be safely used in the context of quantum attacks, for instance to combine a well-established but only classically-secure KEM with a candidate KEM that is believed to be quantum-secure.

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