Lg Electronics Inc.

University of São Paulo

Eduardo Lopes Cominetti

Marcos Vinicius M Silva

Harsh Kupwade Patil

Marcos Antonio Simplicio, Jr

Jefferson E Ricardini

Jefferson E Ricardini Fernandez

Leonardo T D Ferraz

Harsh Kupwade-Patil

Jefferson E Ricardini F De Oliveira

Jefferson B Ricardini

Jefferson E Ricardini Fernandes De Oliveira

Jr Marcos A Simplicio

Leonardo TD Ferraz

Junior Marcos A Simplicio

To revoke a digital certificate, activation of the digital certificate is blocked by withholding an activation code from the certificate user. The certificates are generated by a plurality of entities in a robust process that preserves user privacy (e.g. anonymity) even in case of collusion of some of the entities. The process is suitable for connected vehicles, e.g. as an improvement for Security Credential Management System (SCMS).

Cryptographic methods and systems using activation codes for digital certificate revocation

Digital certificates are generated for devices by a Certificate Authority (CA), which communicates with devices via another entity—registration authority (RA)—so that the CA and RA cannot associate certificates with devices. Each certificate is associated with a public signature key, and with a public encryption key used by CA to encrypt the certificate to hide it from the RA. Both keys are derived by CA from a single key. For example, the signature key can be derived from the public encryption key rather than generated independently. However, high security is obtained even when the CA does not sign the encrypted certificate. Reduced bandwidth and computational costs are obtained as a result. Other embodiments are also provided.

Cryptographic methods and systems for managing digital certificates

According to some embodiments, systems and methods are provided for revoking one or more of a plurality of entities in a vehicular public-key infrastructure. The systems and methods balance privacy and efficiency by distributing activation codes according to various approaches, including a direct request approach, a fixed-size subset approach, and a variable-size subset approach.

Balancing privacy and efficiency for revocation in vehicular public key infrastructures

According to some embodiments, in a Vehicular-to-Everything (V2X) communications environment where vehicles can exchange messages with other entities, including nearby vehicles and pedestrians, systems and methods are provided to implement a mechanism or technique based on hash chaining that allows a large sequence of messages from the same source to be validated by verifying a single digital signature.

Verification of messages using hash chaining

Improved pseudonym certificate management is provided for connected vehicle authentication and other applications. Temporary revocation of a certificate is enabled. With respect to Security Credential Management Systems (SCMS), pre-linkage values can be employed. The pre-linkage values can be encrypted using homomorphic encryption. Other embodiments are also provided.

Cryptographic methods and systems for managing digital certificates with linkage values

Embodiments described herein provide a tree-based key management protocol with enhanced computational and bandwidth efficiency. A tree structure including a plurality of nodes is formulated according to modules in a vehicle. A group key and a blinded key are computed for a leaf node from the plurality of nodes based at least in part on a multiplication operation defined in an ecliptic curve group. Or a group key and a blinded key are recursively computed for a non-leaf node based at least in part on a key derivation function and the multiplication operation involving a group key and a blinded key corresponding to nodes that is one level down to the non-leaf node.

Systems and methods for efficient key management in a vehicular intranet

To revoke a digital certificate (), activation of the digital certificate is blocked by withholding an activation code from the certificate user (). The certificates are generated by a plurality of entities () in a robust process that preserves user privacy (e.g. anonymity) even in case of collusion of some of the entities. The process is suitable for connected vehicles, e.g. as an improvement for Security Credential Management System (SCMS).

Cryptographic methods and systems using blinded activation codes for digital certificate revocation

Pseudonym digital certificates () are generated for devices () by a Pseudonym Certificate Authority (PCA), which communicates with devices via another entity&#x2014;registration authority (RA)&#x2014;so that the PCA and RA cannot associate certificates with devices. Each certificate is associated with a public signature key, and with a public encryption key used by PCA to encrypt the certificate to hide it from the RA. Both keys are derived by PCA from a single key. For example, the signature key can be derived from the public encryption key rather than generated independently. However, high security is obtained even when the PCA does not sign the encrypted certificate. Reduced bandwidth and computational costs are obtained as a result. Other embodiments are also provided.

Improved pseudonym certificate management is provided for connected vehicle authentication and other applications. Temporary revocation of a certificate is enabled. With respect to Security Credential Management Systems (SCMS), linkage authorities can be eliminated without compromising the system security. Other embodiments are also provided.

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São Paulo, Brazil

Eduardo Lopes Cominetti