PRISMACLOUD
PRIvacy & Security MAintaining Services in the CLOUD
08Jan
Practical Witness Encryption for Algebraic Languages Or How to Encrypt Under Groth-Sahai Proofs
Witness encryption (WE) is a recent powerful encryption paradigm, which allows to encrypt a message using the description of a hard problem (a word in an NP-language) and someone who knows a solution to this problem (a witness) is...
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14Dec
Revisiting Proxy Re-Encryption: Forward Secrecy, Improved Security, and Applications
We revisit the notion of proxy re-encryption (PRE), an enhanced public-key encryption primitive envisioned by Blaze et al. (EUROCRYPT 1998) and formalized by Ateniese et al. (NDSS 2005). PRE allows to craft fine-granular re-encryption keys in order to equip...
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27Nov
Short Double- and N-Times-Authentication-Preventing Signatures from ECDSA and More
Double-authentication-preventing signatures (DAPS) are signatures designed with the aim that signing two messages with an identical first part (called address) but different second parts (called payload) allows to publicly extract the secret signing key from two such signatures. A...
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02Oct
Agile Cryptographic Solutions for the Cloud
Cloud computing, with its estimated market size of 150 billion USD annual turnover, is one of the major growth areas in information and communication technologies today. As a paradigm building on outsourcing of storage and processing, cloud computing suffers...
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08Sep
Post-Quantum Zero-Knowledge and Signatures from Symmetric-Key Primitives
We propose a new class of post-quantum digital signature schemes that: (a) derive their security entirely from the security of symmetric-key primitives, believed to be quantum-secure, and (b) have extremely small keypairs, and, (c) are highly parameterizable. In our...
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02Aug
MoPS: A Modular Protection Scheme for Long-Term Storage
Current trends in technology, such as cloud computing, allow outsourcing the storage, backup, and archiving of data. This provides efficiency and flexibility, but also poses new risks for data security. It in particular became crucial to develop protection schemes...
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02Aug
Linearly Homomorphic Authenticated Encryption with Provable Correctness and Public Verifiability
In this work the first linearly homomorphic authenticated encryption scheme with public verifiability and provable correctness, called LEPCoV , is presented. It improves the initial proposal by avoiding false negatives during the verification algorithm. This work provides a detailed...
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02Aug
Position Paper: The Past, Present, and Future of Sanitizable and Redactable Signatures
Sanitizable signature schemes (SSS), as well as redactable signature schemes (RSS), gained a lot of attention in the recent past. In a nutshell, both types of signature schemes allow to alter signed data in a controlled way by a,...
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02Aug
The Archistar Secret-Sharing Backup Proxy
Cloud-Storage has become part of the standard toolkit for enterprise-grade computing. While being cost-and energy-eecient, cloud storage's availability and data conndentiality can be problematic. A common approach of mitigating those issues are cloud-of-cloud solutions. Another challenge is the integration...
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13Jul
Evidence-Based Trust Mechanism Using Clustering Algorithms for Distributed Storage Systems
In distributed storage systems, documents are shared among multiple Cloud providers and stored within their respective storage servers. In social secret sharing-based distributed storage systems, shares of the documents are allocated according to the trustworthiness of the storage servers....
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