Published papers

To receive effective treatment during emergency response due to seizures or unforeseen accidents, a patient with intractable diseases must disclose information about their disease to an emergency physician. If the patient loses consciousness while traveling, the patient should disclose this information to a companion in advance. However, disclosing this information to a companion is undesirable because the information is confidential. Thus, we propose a system that discloses specific information on intractable diseases only when an emergency physician has verified they possess a medical license. Otherwise, the proposed system only discloses appropriate first aid information. We implemented a prototype of the proposed under the assumption that a physician has a digital medical license based on verifiable credentials (i.e., a standard for digital credentials). With this system, the patient does not disclose confidential information to the patient's companion but does disclose necessary information to the emergency physician.

This paper proposes a new SRv6 End behavior, called End.AN.NF, integrating Linux netfilter as a network function for service function chaining by Segment Routing (SR). End.AN.NF allows netfilter-based applications to be executed as SR-Aware applications without modification, as it applies netfilter to inner packets encapsulated in SRv6 while performing the basic SRv6 End behavior. Furthermore, End.AN.NF utilizes the argument of the segment identifiers to mark packets. Consequently, this enables netfilter-based applications to match the marks on packet buffers and change rules to be applied. We implemented End.AN.NF on the Linux kernel and evaluated its performance. The evaluation shows that End.AN.NF achieves 27% higher throughput and 3.0 microseconds lower latency than applying netfilter to SRv6-encapsulated inner packets by End.DT4 and H.Encaps.

To resolve disputes between servicers providing web services and their users, non-repudiable evidence is crucial because it allows one party to dismiss the denial of facts or false allegations. We propose a logger that securely records web requests and responses in a Trusted Execution Environment (TEE) to generate non-repudiable evidence for web services, which we call LogNEWT: Logger for Non-rEpudiation of Web with TEE. LogNEWT solves security issues in deploying LibSEAL to practical web services, i.e., logger-bypassing, undefined user management, and complex logger verification. In addition, LogNEWT can be transparently deployed to the existing web services.