Nec Corporation

Sebastien Andreina

Ghassan Karame

Giorgia Azzurra Marson

Wenting Li

Alessandro Sforzin

Maja Schwarz

Lorenzo Alluminio

Rahul Bobba

Pascal Zimmer

A method for registering a mining computing entity (MCE) with a trusted execution environment entity (TEEE) in a blockchain of a distributed blockchain consensus network (DBCN), based on a proof-of-stake protocol, includes determining public signing information, secret signing information, and a registration timestamp and determining public account information and secret account information for a virtual wallet of the blockchain. The method further includes generating attestation information based on signing integrity information and hashing the public signing information and the public account information, and based on the attestation information, obtaining, from an attestation providing entity (APE), proving information. The method also includes sending, to the blockchain, a registration transaction that is signed with the secret account information, and registering the MCE to the blockchain.

Method for signing a new block in a decentralized blockchain consensus network

A method for secure chain division of a satellite chain by a validator node of a permission-based blockchain system includes executing, by communicating with a set of validator nodes of an original satellite chain of the blockchain system, a validator assignment scheme that splits the set of validator nodes of the original satellite chain into subsets of validator nodes of child chains of the original satellite chain, and running, by communicating with the validator nodes of the respective subsets, a reconfiguration protocol to set up the respective child chains and sending, to an identity management component that maintains identity information of all members of the blockchain system in a registry, a configuration update to record the division of the original satellite chain and corresponding creation of the child chains.

Method and system for scaling blockchains via secure chain division

A method for thwarting attacks on a machine-learning (ML) model is provided. The method includes determining, by the ML model, a classification vector based on an input. The method further includes evaluation the classification vector based on a threshold parameter to determine a threshold result. The method also includes outputting a classification prediction based on the threshold result.

Method and system for thwarting attacks on machine-learning as a service

Methods and systems for supporting trusted communication between nodes from different blockchains are provided. The method comprises using a bootstrapping service for bootstrapping trust among blockchains of a group of federated blockchains. The bootstrapping service records security parameters of the federated blockchains. The security parameters include information on consensus configurations of the federated blockchains.

Bootstrapping root of trust for federated blockchains

A method for sharing of digital health data in a travel environment is provided. Traveler's identities are managed using a distributed ledger system, that includes a global identity blockchain, security blockchains, and a health blockchain. The method comprises sending a request for predetermined number of health data records, receiving consecutive access keys for the requested records and a zero knowledge proof, verifying the zero knowledge proof, wherein the zero knowledge proof validates a latest access key of the consecutive access keys. Upon verification, retrieving the health data records from the health blockchain based on hashed access keys, wherein the hashed access keys are generated from the consecutive access keys, and verifying the consecutive access keys provided by the traveler using hashed previous access keys included in the retrieved health data records, to determine whether the traveler has provided the access keys required for the retrieved health data records as requested.

Method and distributed ledger system for supporting sharing of digital health data of travelers in a travel environment

A method for execution of a Byzantine Fault Tolerant (BFT) protocol among a number of participating nodes of a network includes: receiving, by a primary node of the BFT protocol, a transaction request, applying, by the primary node, a data dissemination protocol for distributing the transaction request among the participating nodes via a data-plane of the network, and generating, by the primary node, a hash of the transaction request and requesting consensus among the participating nodes via a control-plane of the network using the hash of the transaction request.

Method and system for execution of a byzantine fault tolerant protocol

A method for supporting sharing of travel history of travelers in airports includes receiving, by a trusted entity of the distributed ledger system, a registration request from a traveler via a traveler application. The registration request provides personal information of the traveler to the trusted entity. The method further includes generating, by the trusted entity, a public key for the traveler using an identity-based encryption mechanism and sending, from the trusted entity to the global identity blockchain, a registration transaction with respect to the traveler. The registration transaction comprises the public key of the traveler. The method further includes recording a travel history that includes all travel tickets of the traveler, wherein a Merkle tree of all the travel tickets of the traveler is generated. The Merkle tree has a Merkle root, and the Merkle root of the Merkle tree is stored in the global identity blockchain.

Method for supporting sharing of travel history of travelers in airports

A method for supporting identity management of travelers in an airport using a distributed ledger system includes receiving, by a global identity blockchain, a registration request from a traveler via a traveler device. The registration request includes a commitment for identity data that is uploaded by the traveler in a secure cloud storage. The method further includes recording the commitment in the global identity blockchain, receiving, by the global identity blockchain, a result of an identity verification with respect to the traveler from a verifier entity, recording the result in the global identity blockchain, and receiving, by a security blockchain, a ticket registration transaction issued by an airline entity. The ticket registration transaction comprises a unique traveler ID of the traveler. The method further includes issuing, by the security blockchain, an access control list update upon reception of consent by the traveler.

Method and distributed ledger system for supporting identity management of travelers in an airport

A method for securing a genuine machine learning model against adversarial samples includes the steps of attaching a trigger to a sample to be classified and classifying the sample with the trigger attached using a backdoored model that has been backdoored using the trigger. In a further step, it is determined whether an output of the backdoored model is the same as a backdoor class of the backdoored model, and/or an outlier detection method is applied to logits compared to honest logits that were computed using a genuine sample. These steps are repeated using different triggers and backdoored models respectively associated therewith. It is compared a number of times that an output of the backdoored models is not the same as the respective backdoor class, and/or a difference determined by applying the outlier detection method, against one or more thresholds so as to determine whether the sample is adversarial.

Securing machine learning models against adversarial samples through backdoor misclassification

A method for securing an interblockchain transaction includes receiving, from a first user application, a registration request including a first permissioned blockchain public key and a first permissionless blockchain public key. The method also includes performing, by the processing circuitry, receiving, from a second user application, a second registration request including a second permissioned blockchain public key and a second permissionless blockchain public key. The permissioned blockchain public keys are valid on the permissioned blockchain and the permissionless blockchain public keys are valid on the permissionless public blockchain. In addition, the method includes receiving, from the first user application, a transaction identification, the transaction identification identifying a first transfer transaction executed on the permissionless public blockchain. The transaction identification identifies the first and second permissionless blockchain public keys.

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Heidelberg, Germany

Sebastien Andreina