In most domains where declarative policies are employed, it is typically the executor of the policy who performs policy evaluation, and not the subjects of policies. However, this approach has evident drawbacks from the trust, transparency and privacy aspects, especially when the subjects are natural persons. Building on recent developments in noninteractive zero-knowledge proofs and the technologies and standards supporting Self-Sovereign Indentity solutions, in this paper, we propose Self-Evaluated Policies, which move policy evaluation to the subject and leave the executor in a (zero-knowledge) proof-checking role. We present an SSI-based system model, propose a proof-tree-checking computational model for zero-knowledge proofs over the evaluations of Prolog-based policies, and describe a Circombased prototype.

Cross-organizational, blockchain-based distributed ledger networks in general, and those based on Hyperledger Fabric in particular, have an architecture which can be adapted to specific application requirements. However, network design can be a particularly challenging task, as the connection between architectural and deployment decisions and extra-functional properties can be subtle and the requirements may contradict each other, requiring trade-offs.

The last few years have seen a steep increase in blockchain interoperability research. Most solutions connect public blockchains, where the main cross-chain use case is token transfer. By-design platform transparency, tamper resistance, and auditability make blockchains a candidate infrastructure for Central Bank Digital Currencies (CBDCs), but bridging CBDCs is an important missing piece in that scenario. In this paper, we leverage an asset transfer protocol, SATP, to define an extendable and dependable blockchain interoperability middleware that can bridge CBDC between Hyperledger Fabric and EVM-based permissioned blockchains. The key interoperation enabler in the solution is a shared asset definition enforced by both sides of the bridge, accompanied by a mapping between Fabric identities and Ethereum addresses for identity management. We implemented our design using Hyperledger Cacti. A preliminary evaluation shows that latency is more influenced by the ledgers than the bridging components.

Fault injection (FI) is an experimental methodology used in a wide range of scenarios for validating the fault resilience of applications, especially safety-critical ones. A sufficiently thoroughgoing evaluation produces a significant amount of data regarding the behavior of software components or entire systems in the presence of faults. The core questions that practitioners using fault injection face are 1) how to extract and represent information, 2) how to effectively analyze that data and how to utilize the gained knowledge to improve the FI process. Previous works addressing these questions relied mainly on ad hoc approaches. The current paper presents a modern view of these problems, preparing and executing the knowledge extraction by exploratory (big) data analysis, methods, and tools. A real use-case based on FI campaigns composed of thousands of fault injections into a virtualized system indicates the huge potential of the approach. The outcome is the discovery of an opportunity for a drastic speed-up of the FI process unrevealed by the traditional methodology.

During the planning of an UMTS radio network, there is a natural need for a base station positioning procedure. Good coverage at an acceptable level of network installation and maintaining costs, low interference and uniform interface load are the main requirements. In this paper we present an approach based on simulated annealing.