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Multi-key Security: The Even-Mansour Construction Revisited [chapter]

Nicky Mouha, Atul Luykx
2015 Lecture Notes in Computer Science  
We hope that the results in this paper will further encourage the use of the Even-Mansour construction, especially when the secure and efficient implementation of a key schedule would result in a significant  ...  In this paper, we prove that if a small number of plaintexts are encrypted under multiple independent keys, the Even-Mansour construction surprisingly offers similar security as an ideal block cipher with  ...  the Even-Mansour construction.  ... 
doi:10.1007/978-3-662-47989-6_10 fatcat:o3izd5smcrcvloiybvbbfvfcje

Revisiting Key-Alternating Feistel Ciphers for Shorter Keys and Multi-user Security [chapter]

Chun Guo, Lei Wang
2018 Lecture Notes in Computer Science  
Our results hold in the multi-user setting as well, constituting the first non-trivial multi-user provable security results on Feistel ciphers.  ...  We finally demonstrate applications of our results on designing keyschedules and instantiating keyed sponge constructions. To obtain a 2n-bit BC, the IEM model requires 2n-bit permutations.  ...  Finally we thank Yaobin Shen for identifying a flaw (in Lemma 5) in an earlier version of the proof, and Christian Rechberger and Damian Vizár for the discussion on multi-party computation.  ... 
doi:10.1007/978-3-030-03326-2_8 fatcat:koiebntubvb6hdi4plkhjc3n7q

Key-Alternating Ciphers and Key-Length Extension: Exact Bounds and Multi-user Security [chapter]

Viet Tung Hoang, Stefano Tessaro
2016 Lecture Notes in Computer Science  
This paper revisits the concrete security of key-alternating ciphers and key-length extension schemes, with respect to tightness and multi-user security.  ...  On the way, we also provide the first explicit treatment of multi-user security for key-length extension, which is particularly relevant given the significant security loss of block ciphers (even if ideal  ...  Finally, we thank the CRYPTO 2016 reviewers for many insightful comments. This research was partially supported by NSF grants CNS-1423566 and CNS-1553758 (CA-REER).  ... 
doi:10.1007/978-3-662-53018-4_1 fatcat:ugj5skptafc3dfafymdkfr2ag4

Multi-key Analysis of Tweakable Even-Mansour with Applications to Minalpher and OPP

Zhiyuan Guo, Wenling Wu, Renzhang Liu, Liting Zhang
2017 IACR Transactions on Symmetric Cryptology  
The tweakable Even-Mansour construction generalizes the conventional Even-Mansour scheme through replacing round keys by strings derived from a master key and a tweak.  ...  In the present paper, we evaluate the multi-key security of TEM-1, one of the most commonly used one-round tweakable Even-Mansour schemes (formally introduced at CRYPTO 2015), which is constructed from  ...  The authors would like to thank all anonymous referees for their valuable comments that greatly improve the manuscript.  ... 
doi:10.46586/tosc.v2016.i2.288-306 fatcat:2dg5ktpl3vavzmvl6vcpxkq23q

Multi-key Analysis of Tweakable Even-Mansour with Applications to Minalpher and OPP

Zhiyuan Guo, Wenling Wu, Renzhang Liu, Liting Zhang
2017 IACR Transactions on Symmetric Cryptology  
The tweakable Even-Mansour construction generalizes the conventional Even-Mansour scheme through replacing round keys by strings derived from a master key and a tweak.  ...  In the present paper, we evaluate the multi-key security of TEM-1, one of the most commonly used one-round tweakable Even-Mansour schemes (formally introduced at CRYPTO 2015), which is constructed from  ...  The authors would like to thank all anonymous referees for their valuable comments that greatly improve the manuscript.  ... 
doi:10.13154/tosc.v2016.i2.288-306 dblp:journals/tosc/GuoWLZ16 fatcat:besakbj35bgbpm2mfqfocmmwda

Full-State Keyed Duplex with Built-In Multi-user Support [chapter]

Joan Daemen, Bart Mennink, Gilles Van Assche
2017 Lecture Notes in Computer Science  
The keyed duplex construction was introduced by Bertoni et al. (SAC 2011) and recently generalized to full-state absorption by Mennink et al. (ASIACRYPT 2015).  ...  We present a generalization of the full-state keyed duplex that natively supports multiple instances by design, and perform a security analysis that improves over that of Mennink et al. in terms of a more  ...  [2] considered the security of the outer-and inner-keyed sponge in the multi-target setting, a proof which internally featured a security analysis of the Even-Mansour blockcipher in the multi-target  ... 
doi:10.1007/978-3-319-70697-9_21 fatcat:wrycumeznjgylcwhytzyxoljui

Multi-key Authenticated Encryption with Corruptions: Reductions Are Lossy [chapter]

Tibor Jager, Martijn Stam, Ryan Stanley-Oakes, Bogdan Warinschi
2017 Lecture Notes in Computer Science  
By appropriate settings of the parameters of the framework, we obtain multi-key variants of many of the existing single-key security notions.  ...  from the multi-key game to a standard single-key game necessarily incurs a linear loss in the number of keys.  ...  The authors would also like to thank the anonymous TCC reviewers for their constructive comments on our paper.  ... 
doi:10.1007/978-3-319-70500-2_14 fatcat:afehqm23tzhqff3bfqemgifzoy

Quantum-Secure Symmetric-Key Cryptography Based on Hidden Shifts [chapter]

Gorjan Alagic, Alexander Russell
2017 Lecture Notes in Computer Science  
We then establish, under this assumption, the qCPA-security of several such Hidden Shift adaptations of symmetric-key constructions.  ...  The vulnerable cryptosystems include the Even-Mansour block cipher, the three-round Feistel network, the Encrypted-CBC-MAC, and many others.  ...  motivates the classical Even-Mansour block-cipher construction.  ... 
doi:10.1007/978-3-319-56617-7_3 fatcat:x7btopqmzbguzlsunujxqfr7be

Constructions of Beyond-Birthday Secure PRFs from Random Permutations, Revisited

Jiehui Nan, Ping Zhang, Honggang Hu
2021 Entropy  
Furthermore, we use only one random permutation to construct parallelizable and succinct beyond-birthday secure PRFs in the multi-key setting, and then tweak this new construction.  ...  In CRYPTO 2019, Chen et al. showed how to construct pseudorandom functions (PRFs) from random permutations (RPs), and they gave one beyond-birthday secure construction from sum of Even-Mansour, namely  ...  In [15] , the construction SoEM22 (which means sum of one-round Even-Mansour based on two independent permutations) was proved beyond-birthday secure in the single-key setting.  ... 
doi:10.3390/e23101296 pmid:34682020 fatcat:u62i4fo6f5cfvkyrjtmkfnx6cm

Optimally Secure Block Ciphers from Ideal Primitives [chapter]

Stefano Tessaro
2015 Lecture Notes in Computer Science  
This paper addresses the question of finding new constructions achieving the highest possible security level under minimal assumptions in such ideal models.  ...  We present a new block-cipher construction, derived from the Swap-or-Not construction by Hoang et al. (CRYPTO '12).  ...  Introduction Several recent works provide ideal-model security proofs for key-alternating (i.e., Even-Mansour like) ciphers [25, 23, 14, 2, 50, 16, 15, 19, 26, 31, 17] and for Feistel-like ciphers [  ... 
doi:10.1007/978-3-662-48800-3_18 fatcat:bffmqpewvrddfpsyghe5jlhyoq

Conclusions and Policy Recommendations [chapter]

Sarah Wolff
2021 The Security Sector Governance–Migration Nexus: Rethinking how Security Sector Governance matters for migrants' rights  
Revisiting the ethics of SSR actors is key in that respect. SSR actors are themselves a solution since they are 'reformers in their own right' (Donais, 2018: 34) .  ...  (European Ombudsman, 2018: 21) Therefore, partnerships with civil society, or even the training of the security sector, and state authorities dealing directly with refugees and migrants are key to filtering  ...  interests of researchers, policymakers and practitioners in the elds of development, peace, and security.  ... 
doi:10.5334/bcl.f fatcat:yj6exj332zg6pmo6tfupuytwte

Dispelling Myths on Superposition Attacks: Formal Security Model and Attack Analyses [article]

Luka Music, Céline Chevalier, Elham Kashefi
2020 arXiv   pre-print
Conversely, security models considering computational security assume that all supposedly classical messages are measured, which forbids by construction the analysis of superposition attacks.  ...  We use this newly imparted knowledge to construct the first concrete protocol for Secure Two-Party Computation that is resistant to superposition attacks.  ...  Acknowledgments This work was supported in part by the French ANR project CryptiQ (ANR-18-CE39-0015).  ... 
arXiv:2007.00677v1 fatcat:d725zyxxm5emzpsi2arzxt45q4

Cryptanalysis Against Symmetric-Key Schemes with Online Classical Queries and Offline Quantum Computations [chapter]

Akinori Hosoyamada, Yu Sasaki
2018 Lecture Notes in Computer Science  
Banegas and Bernstein [BB17] showed that the computational cost T of the multi-target preimage search in the free communication model is T =Õ N Q·D .  ...  Banegas and Bernstein [BB17] showed that the computational cost T of the multi-target preimage search in the realistic communication model is T =Õ N Q·D 1/2 .  ...  Security of Chaskey is the same level as the Even-Mansour construction.  ... 
doi:10.1007/978-3-319-76953-0_11 fatcat:5zpkumcntzdkxnnbep6in5sr6m

Simpira v2: A Family of Efficient Permutations Using the AES Round Function [chapter]

Shay Gueron, Nicky Mouha
2016 Lecture Notes in Computer Science  
Mouha, N., Luykx, A.: Multi-key Security: The Even-Mansour Construction Re- visited. In: CRYPTO 2015. LNCS, vol. 9215, pp. 209–223. Springer (2015) 68.  ...  In order to achieve security up to about 2128 queries against all attacks in the multi-key setting, the Even-Mansour construction requires a permutation of at least 256 bits.  ... 
doi:10.1007/978-3-662-53887-6_4 fatcat:3wjksrkgqzgo3pg57fpdq6cffu

On the Resilience of Even-Mansour to Invariant Permutations

Bart Mennink, Samuel Neves
2021 Designs, Codes and Cryptography  
We first formalize the use of invariant cryptographic permutations from a security perspective, and analyze the Even-Mansour block cipher construction.  ...  From a practical side, we apply the derived security bounds to the case where the Even-Mansour construction is instantiated with the 512-bit ChaCha permutation, and derive a distinguishing attack against  ...  Multi-Key Security In the random permutation model, the Even-Mansour construction is known to admit only a small loss: it is proven to be secure up to (q 2 +2qp)/2 κ [88] .  ... 
doi:10.1007/s10623-021-00850-2 fatcat:g7gxepprufbkdgxlhsruvia45y
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