Experiences in teaching grid computing to advanced level students

The development of teaching materials for future software engineers is critical to the long term success of the grid. At present however there is considerable turmoil in the grid community both within the standards and the technology base underpinning these standards. In this context, it is especially challenging to develop teaching materials that have some sort of lifetime beyond the next wave of grid middleware and standards. In addition, the current way in which grid security is supported and delivered has two key problems. Firstly in the case of the UK e-Science community, scalability issues arise from a central certificate authority. Secondly, the current security mechanisms used by the grid community are not line grained enough. In this paper we outline how these issues are being addressed through the development of a grid computing module supported by an advanced authorisation infrastructure at the University of Glasgow

Enhanced security architecture for support of credential repository in grid computing.

Grid Computing involves heterogeneous computers and resources, multiple administrative domains and the mechanisms and techniques for establishing and maintaining effective and secure communications between devices and systems. Both authentication and authorization are required. Current authorization models in each domain vary from one system to another, which makes it difficult for users to obtain authorization across multiple domains at one time. We propose an enhanced security architecture to provide support for decentralized authorization based on attribute certificates which may be accessed via the Internet. This allows the administration of privileges to be widely distributed over the Internet in support of autonomy for resource owners and providers. In addition, it provides a uniform approach for authorization which may be used by resource providers from various domains. We combine authentication with the authorization mechanism by using both MyProxy online credential repository and LDAP directory server. In our architecture, we use MyProxy server to store identity certificates for authentication, and utilize an LDAP server-based architecture to store attribute certificates for authorization. Using a standard web browser, a user may connect to a grid portal and allow the portal to retrieve those certificates in order to access grid resources on behalf of the user. Thus, our approach can make use of the online credential repository to integrate authentication, delegation and attribute based access control together to provide enhanced, flexible security for grid system. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .C54. Source: Masters Abstracts International, Volume: 43-01, page: 0231. Adviser: R. D. Kent. Thesis (M.Sc.)--University of Windsor (Canada), 2004

Towards Practical Access Control and Usage Control on the Cloud using Trusted Hardware

Cloud-based platforms have become the principle way to store, share, and synchronize files online. For individuals and organizations alike, cloud storage not only provides resource scalability and on-demand access at a low cost, but also eliminates the necessity of provisioning and maintaining complex hardware installations. Unfortunately, because cloud-based platforms are frequent victims of data breaches and unauthorized disclosures, data protection obliges both access control and usage control to manage user authorization and regulate future data use. Encryption can ensure data security against unauthorized parties, but complicates file sharing which now requires distributing keys to authorized users, and a mechanism that prevents revoked users from accessing or modifying sensitive content. Further, as user data is stored and processed on remote ma- chines, usage control in a distributed setting requires incorporating the local environmental context at policy evaluation, as well as tamper-proof and non-bypassable enforcement. Existing cryptographic solutions either require server-side coordination, offer limited flexibility in data sharing, or incur significant re-encryption overheads on user revocation. This combination of issues are ill-suited within large-scale distributed environments where there are a large number of users, dynamic changes in user membership and access privileges, and resources are shared across organizational domains. Thus, developing a robust security and privacy solution for the cloud requires: fine-grained access control to associate the largest set of users and resources with variable granularity, scalable administration costs when managing policies and access rights, and cross-domain policy enforcement. To address the above challenges, this dissertation proposes a practical security solution that relies solely on commodity trusted hardware to ensure confidentiality and integrity throughout the data lifecycle. The aim is to maintain complete user ownership against external hackers and malicious service providers, without losing the scalability or availability benefits of cloud storage. Furthermore, we develop a principled approach that is: (i) portable across storage platforms without requiring any server-side support or modifications, (ii) flexible in allowing users to selectively share their data using fine-grained access control, and (iii) performant by imposing modest overheads on standard user workloads. Essentially, our system must be client-side, provide end-to-end data protection and secure sharing, without significant degradation in performance or user experience. We introduce NeXUS, a privacy-preserving filesystem that enables cryptographic protection and secure file sharing on existing network-based storage services. NeXUS protects the confidentiality and integrity of file content, as well as file and directory names, while mitigating against rollback attacks of the filesystem hierarchy. We also introduce Joplin, a secure access control and usage control system that provides practical attribute-based sharing with decentralized policy administration, including efficient revocation, multi-domain policies, secure user delegation, and mandatory audit logging. Both systems leverage trusted hardware to prevent the leakage of sensitive material such as encryption keys and access control policies; they are completely client-side, easy to install and use, and can be readily deployed across remote storage platforms without requiring any server-side changes or trusted intermediary. We developed prototypes for NeXUS and Joplin, and evaluated their respective overheads in isolation and within a real-world environment. Results show that both prototypes introduce modest overheads on interactive workloads, and achieve portability across storage platforms, including Dropbox and AFS. Together, NeXUS and Joplin demonstrate that a client-side solution employing trusted hardware such as Intel SGX can effectively protect remotely stored data on existing file sharing services

CamFlow: Managed Data-sharing for Cloud Services

A model of cloud services is emerging whereby a few trusted providers manage the underlying hardware and communications whereas many companies build on this infrastructure to offer higher level, cloud-hosted PaaS services and/or SaaS applications. From the start, strong isolation between cloud tenants was seen to be of paramount importance, provided first by virtual machines (VM) and later by containers, which share the operating system (OS) kernel. Increasingly it is the case that applications also require facilities to effect isolation and protection of data managed by those applications. They also require flexible data sharing with other applications, often across the traditional cloud-isolation boundaries; for example, when government provides many related services for its citizens on a common platform. Similar considerations apply to the end-users of applications. But in particular, the incorporation of cloud services within `Internet of Things' architectures is driving the requirements for both protection and cross-application data sharing. These concerns relate to the management of data. Traditional access control is application and principal/role specific, applied at policy enforcement points, after which there is no subsequent control over where data flows; a crucial issue once data has left its owner's control by cloud-hosted applications and within cloud-services. Information Flow Control (IFC), in addition, offers system-wide, end-to-end, flow control based on the properties of the data. We discuss the potential of cloud-deployed IFC for enforcing owners' dataflow policy with regard to protection and sharing, as well as safeguarding against malicious or buggy software. In addition, the audit log associated with IFC provides transparency, giving configurable system-wide visibility over data flows. [...]Comment: 14 pages, 8 figure

Secure Hardware Enhanced MyProxy: A Ph.D. Thesis Proposal

In 1976, Whitfield Diffie and Martin Hellman demonstrated how New Directions In Cryptography could enable secure information exchange between parties that do not share secrets. In order for public key cryptography to work in modern distributed environments, we need an infrastructure for finding and trusting other parties\u27 public keys (i.e., a PKI). A number of useful applications become possible with PKI. While the applications differ in how they use keys (e.g., S/MIME uses the key for message encryption and signing, while client-side SSL uses the key for authentication), all applications share one assumption: users have keypairs. In previous work, we examined the security aspects of some of the standard keystores and the their interaction with the OS. We concluded that desktops are not safe places to store private keys, and we demonstrated the permeability of keystores such as the default Microsoft keystore and the Mozilla keystore. In addition to being unsafe, these desktop keystores have the added disadvantage of being immobile. In other previous work, we examined trusted computing. In industry, a new trusted computing initiative has emerged: the Trusted Computing Platform Alliance (TCPA) (now renamed the Trusted Computing Group (TCG)). The goal of the TCG design is lower-assurance security that protects an entire desktop platform and is cheap enough to be commercially feasible. Last year, we built a trusted computing platform based on the TCG specifications and hardware. The picture painted by these previous projects suggests that common desktops are not secure enough for use as PKI clients, and trusted computing can improve the security of client machines. The question that I propose to investigate is: Can I build a system which applies trusted computing hardware in a reasonable manner in order to make desktops usable for PKI? My design begins with the Grid community\u27s MyProxy credential repository, and enhances it to take advantage of secure hardware on the clients, at the repository, and in the policy framework. The result is called Secure Hardware Enhanced MyProxy

DroidCap: OS Support for Capability-based Permissions in Android

We present DroidCap, a retrofitting of Android’s central Binder IPC mechanism to change the way how permissions are being represented and managed in the system. In DroidCap, permissions are per-process Binder object capabilities. DroidCap's design removes Android’s UID-based ambient authority and allows the delegation of capabilities between processes to create least-privileged protection domains efficiently. With DroidCap, we show that object capabilities as underlying access control model integrates naturally and backward-compatible into Android’s stock permission model and application management. Thus, our Binder capabilities provide app developers with a new path to gradually adopting app compartmentalization, which we showcase at two favorite examples from the literature, privilege separated advertisement libraries and least privileged app components

Decentralized Identity and Access Management Framework for Internet of Things Devices

The emerging Internet of Things (IoT) domain is about connecting people and devices and systems together via sensors and actuators, to collect meaningful information from the devices surrounding environment and take actions to enhance productivity and efficiency. The proliferation of IoT devices from around few billion devices today to over 25 billion in the next few years spanning over heterogeneous networks defines a new paradigm shift for many industrial and smart connectivity applications. The existing IoT networks faces a number of operational challenges linked to devices management and the capability of devices’ mutual authentication and authorization. While significant progress has been made in adopting existing connectivity and management frameworks, most of these frameworks are designed to work for unconstrained devices connected in centralized networks. On the other hand, IoT devices are constrained devices with tendency to work and operate in decentralized and peer-to-peer arrangement. This tendency towards peer-to-peer service exchange resulted that many of the existing frameworks fails to address the main challenges faced by the need to offer ownership of devices and the generated data to the actual users. Moreover, the diversified list of devices and offered services impose that more granular access control mechanisms are required to limit the exposure of the devices to external threats and provide finer access control policies under control of the device owner without the need for a middleman. This work addresses these challenges by utilizing the concepts of decentralization introduced in Distributed Ledger (DLT) technologies and capability of automating business flows through smart contracts. The proposed work utilizes the concepts of decentralized identifiers (DIDs) for establishing a decentralized devices identity management framework and exploits Blockchain tokenization through both fungible and non-fungible tokens (NFTs) to build a self-controlled and self-contained access control policy based on capability-based access control model (CapBAC). The defined framework provides a layered approach that builds on identity management as the foundation to enable authentication and authorization processes and establish a mechanism for accounting through the adoption of standardized DLT tokenization structure. The proposed framework is demonstrated through implementing a number of use cases that addresses issues related identity management in industries that suffer losses in billions of dollars due to counterfeiting and lack of global and immutable identity records. The framework extension to support applications for building verifiable data paths in the application layer were addressed through two simple examples. The system has been analyzed in the case of issuing authorization tokens where it is expected that DLT consensus mechanisms will introduce major performance hurdles. A proof of concept emulating establishing concurrent connections to a single device presented no timed-out requests at 200 concurrent connections and a rise in the timed-out requests ratio to 5% at 600 connections. The analysis showed also that a considerable overhead in the data link budget of 10.4% is recorded due to the use of self-contained policy token which is a trade-off between building self-contained access tokens with no middleman and link cost

Engineering Trustworthy Systems by Minimizing and Strengthening their TCBs using Trusted Computing

The Trusted Computing Base (TCB) describes the part of an IT system that is responsible for enforcing a certain security property of the system. In order to engineer a trustworthy system, the TCB must be as secure as possible. This can be achieved by reducing the number, size and complexity of components that are part of the TCB and by using hardened components as part of the TCB. Worst case scenario is for the TCB to span the complete IT system. Best case is for the TCB to be reduced to only a strengthened Root of Trust such as a Hardware Security Module (HSM). One such very secure HSMs with many capabilities is the Trusted Platform Module (TPM). This thesis demonstrates how the TCB of a system can be largely or even solely reduced to the TPM for a variety of security policies, especially in the embedded domain. The examined scenarios include the policies for securing of device resident data at rest also during firmware updates, the enforcement of firmware product lines at runtime, the securing of payment credentials in Plug and Charge controllers, the recording of audit trails over attestation data and a very generic role-based access management. In order to allow evaluating these different solutions, the notion of a dynamic lifecycle dimension for a TCB is introduced. Furthermore, an approach towards engineering such systems based on a formal framework is presented. These scenarios provide evidence for the potential to enforce even complex security policies in small and thus strong TCBs. The approach for implementing those policies can often be inspired by a formal methods based engineering process or by means of additive functional engineering, where a base system is expanded by increased functionality in each step. In either case, a trustworthy system with high assurance capabilities can be achieved