Revocable Hierarchical Attribute-based Signatures from Lattices

Attribute-based Signatures (ABS) allow users to obtain attributes from issuing authorities, and sign messages whilst simultaneously proving compliance of their attributes with a verification policy. ABS demands that both the signer and the set of attributes used to satisfy a policy remain hidden to the verifier. Hierarchical ABS (HABS) supporting roots of trust and delegation were recently proposed to alleviate scalability issues in centralised ABS schemes. An important yet challenging property for privacy-preserving ABS is revocation, which may be applied to signers or some of the attributes they possess. Existing ABS schemes lack efficient revocation of either signers or their attributes, relying on generic costly proofs.Moreover, in HABS there is a further need to support revocation of authorities on the delegation paths, which is not provided by existing HABS constructions. This paper proposes a direct HABS scheme with a Verifier-Local Revocation (VLR) property. We extend the original HABS security model to address revocation and develop a new attribute delegation technique with appropriate VLR mechanism for HABS, which also implies the first ABS scheme to support VLR. Moreover, our scheme supports inner-product signing policies, offering a wider class of attribute relations than previous HABS schemes, and is the first to be based on lattices, which are thought to offer post-quantum security

Context dependent revocation in delegated XACML

The XACML standard defines an XML based language for defining access control policies and a related processing model. Recent work aims to add delegation to XACML in order to express the right to administrate XACML policies within XACML itself. The delegation profile draft explains how to validate the right to issue a policy, but there are no provisions for removing a policy. This paper proposes a revocation model for delegated XACML. A novel feature of this model is that whether a revocation is valid or not, depends not only on who issued the revocation, but also on the context in which an attempt to use the revoked policy is done

ViotSOC: Controlling Access to Dynamically Virtualized IoT Services using Service Object Capability

Virtualization of Internet of Things(IoT) is a concept of dynamically building customized high-level IoT services which rely on the real time data streams from low-level physical IoT sensors. Security in IoT virtualization is challenging, because with the growing number of available (building block) services, the number of personalizable virtual services grows exponentially. This paper proposes Service Object Capability(SOC) ticket system, a decentralized access control mechanism between servers and clients to effi- ciently authenticate and authorize each other without using public key cryptography. SOC supports decentralized partial delegation of capabilities specified in each server/- client ticket. Unlike PKI certificates, SOC’s authentication time and handshake packet overhead stays constant regardless of each capability’s delegation hop distance from the root delegator. The paper compares SOC’s security bene- fits with Kerberos and the experimental results show SOC’s authentication incurs significantly less time packet overhead compared against those from other mechanisms based on RSA-PKI and ECC-PKI algorithms. SOC is as secure as, and more efficient and suitable for IoT environments, than existing PKIs and Kerberos