Eleftherios Kokoris Kogias

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Unités associées (3)

Unités associées

Chargement

Cours enseignés par cette personne

Chargement

Domaines de recherche associés (6)

Domaines de recherche associés

Chargement

Publications associées (15)

Publications associées

Chargement

Personnes menant des recherches similaires (145)

Personnes menant des recherches similaires

Chargement

CALYPSO: Private Data Management for Decentralized Ledgers

Enis Ceyhun Alp, Bryan Alexander Ford, Linus Gasser, Philipp Svetolik Jovanovic, Eleftherios Kokoris Kogias

Distributed ledgers provide high availability and integrity, making them a key enabler for practical and secure computation of distributed workloads among mutually distrustful parties. Many practical applications also require strong confidentiality, however. This work enhances permissioned and permissionless blockchains with the ability to manage confidential data without forfeiting availability or decentralization. The proposed Calypso architecture addresses two orthogonal challenges confronting modern distributed ledgers: (a) enabling the auditable management of secrets and (b) protecting distributed computations against arbitrage attacks when their results depend on the ordering and secrecy of inputs. Calypso introduces on-chain secrets, a novel abstraction that enforces atomic deposition of an auditable trace whenever users access confidential data. Calypso provides user-controlled consent management that ensures revocation atomicity and accountable anonymity. To enable permissionless deployment, we introduce an incentive scheme and provide users with the option to select their preferred trustees. We evaluated our Calypso prototype with a confidential document-sharing application and a decentralized lottery. Our benchmarks show that transaction-processing latency increases linearly in terms of security (number of trustees) and is in the range of 0.2 to 8 seconds for 16 to 128 trustees.

2021

Chargement

CALYPSO: Private Data Management for Decentralized Ledgers

Enis Ceyhun Alp, Bryan Alexander Ford, Linus Gasser, Philipp Svetolik Jovanovic, Eleftherios Kokoris Kogias

Distributed ledgers provide high availability and integrity, making them a key enabler for practical and secure computation of distributed workloads among mutually distrustful parties. Many practical applications also require strong confidentiality, however. This work enhances permissioned and permissionless blockchains with the ability to manage confidential data without forfeiting availability or decentralization. The proposed CALYPSO architecture addresses two orthogonal challenges confronting modern distributed ledgers: (a) enabling the auditable management of secrets and (b) protecting distributed computations against arbitrage attacks when their results depend on the ordering and secrecy of inputs. CALYPSO introduces on-chain secrets, a novel abstraction that enforces atomic deposition of an auditable trace whenever users access confidential data. CALYPSO provides user-controlled consent management that ensures revocation atomicity and accountable anonymity. To enable permissionless deployment, we introduce an incentive scheme and provide users with the option to select their preferred trustees. We evaluated our CALYPSO prototype with a confidential document-sharing application and a decentralized lottery. Our benchmarks show that transaction-processing latency increases linearly in terms of security (number of trustees) and is in the range of 0.2 to 8 seconds for 16 to 128 trustees.

ASSOC COMPUTING MACHINERY2020

Chargement

, ,

The present invention concerns a computer-implemented method for secure data exchange between a sender (A) and a recipient (B), wherein the method is performed by the sender (A) and comprises encrypting data using a symmetric key k, creating a write transaction T W , wherein the write transaction T W comprises information usable to derive the symmetric key k and an access policy identifying the recipient (B) as being allowed to decrypt the encrypted data, providing the recipient (B) access to the encrypted data, and sending the write transaction T W to a first group of servers (AC) for being stored in a blockchain data structure maintained by the first group of servers (AC).

2019

Chargement