Keys in the Clouds: Auditable Multi-device Access to Cryptographic Credentials

Personal cryptographic keys are the foundation of many secure services, but storing these keys securely is a challenge, especially if they are used from multiple devices. Storing keys in a centralized location, like an Internet-accessible server, raises serious security concerns (e.g. server compromise). Hardware-based Trusted Execution Environments (TEEs) are a well-known solution for protecting sensitive data in untrusted environments, and are now becoming available on commodity server platforms. Although the idea of protecting keys using a server-side TEE is straight-forward, in this paper we validate this approach and show that it enables new desirable functionality. We describe the design, implementation, and evaluation of a TEE-based Cloud Key Store (CKS), an online service for securely generating, storing, and using personal cryptographic keys. Using remote attestation, users receive strong assurance about the behaviour of the CKS, and can authenticate themselves using passwords while avoiding typical risks of password-based authentication like password theft or phishing. In addition, this design allows users to i) define policy-based access controls for keys; ii) delegate keys to other CKS users for a specified time and/or a limited number of uses; and iii) audit all key usages via a secure audit log. We have implemented a proof of concept CKS using Intel SGX and integrated this into GnuPG on Linux and OpenKeychain on Android. Our CKS implementation performs approximately 6,000 signature operations per second on a single desktop PC. The latency is in the same order of magnitude as using locally-stored keys, and 20x faster than smart cards.Comment: Extended version of a paper to appear in the 3rd Workshop on Security, Privacy, and Identity Management in the Cloud (SECPID) 201

Future consumer mobile phone security: a case study using the data centric security model

In the interconnected world that we live in, traditional security barriers are\ud broken down. Developments such as outsourcing, increased usage of mobile\ud devices and wireless networks each cause new security problems.\ud To address the new security threats, a number of solutions have been suggested,\ud mostly aiming at securing data rather than whole systems or networks.\ud However, these visions (such as proposed by the Jericho Forum [9] and IBM\ud [4]) are mostly concerned with large (inter-) enterprise systems. Until now, it is\ud unclear what data-centric security could mean for other systems and environments.\ud One particular category of systems that has been neglected is that of\ud consumer mobile phones. Currently, data security is usually limited to a PIN\ud number on startup and the option to disable wireless connections. The lack of\ud protection does not seem justified, as these devices have steadily increased in\ud capabilities and capacity; they can connect wirelessly to the Internet and have\ud a high risk of being lost or stolen [8]. This not only puts end users at risk, but\ud also their contacts, as phones can contain privacy sensitive data of many others.\ud For example, if birth dates and addresses are kept with the contact records, in\ud many cases a thief will have enough information to impersonate a contact and\ud steal his identity.\ud Could consumer mobile phones benefit from data-centric security? How\ud useful is data-centric security in this context? These are the core questions we\ud will try to address here

Authentication of Students and Students’ Work in E-Learning : Report for the Development Bid of Academic Year 2010/11

Global e-learning market is projected to reach $107.3 billion by 2015 according to a new report by The Global Industry Analyst (Analyst 2010). The popularity and growth of the online programmes within the School of Computer Science obviously is in line with this projection. However, also on the rise are students’ dishonesty and cheating in the open and virtual environment of e-learning courses (Shepherd 2008). Institutions offering e-learning programmes are facing the challenges of deterring and detecting these misbehaviours by introducing security mechanisms to the current e-learning platforms. In particular, authenticating that a registered student indeed takes an online assessment, e.g., an exam or a coursework, is essential for the institutions to give the credit to the correct candidate. Authenticating a student is to ensure that a student is indeed who he says he is. Authenticating a student’s work goes one step further to ensure that an authenticated student indeed does the submitted work himself. This report is to investigate and compare current possible techniques and solutions for authenticating distance learning student and/or their work remotely for the elearning programmes. The report also aims to recommend some solutions that fit with UH StudyNet platform.Submitted Versio

Secure Portable Execution Environments: A Review of Available Technologies

Live operating systems and virtualisation allow a known, defined, safe and secure execution environment to be loaded in to a PC’s memory and executed with either minimal or possibly no reliance on the PC’s internal hard disk drive. The ability to boot a live operating system or load a virtual environment (containing an operating system) from a USB storage device allows a secure portable execution environment to be created. Portable execution environments have typically been used by technologists, for example to recover data from a failing PC internal hard disk drive or to perform forensic analysis. However, with the commercial potential of portable execution environments becoming realised the requirement for such environments to be secure is becoming increasingly important. To be considered truly secure a portable execution environment should require authentication prior to loading the executing environment (from the USB mass storage device) and provide full encryption of the whole mass storage device. This paper discusses the outcomes from building four portable execution environments, using commercially available and/or freeware technologies. An overview is given of the emerging commercial requirement for secure portable USB execution environments, the security threats addressed and research performed in the area. The technologies and products considered in the review are outlined together with rationale behind the selection. The findings from the implementation of the four portable execution environments are discussed including successes, failures and difficulties encountered. A set of security requirements is defined which is used to gauge the effectiveness of each of the four environments

Boosting usability for Protecting Online Banking Applications Against APTs

With the advent of Advanced Persistent Threats (APTs) and exploits such as Eurograbber, we can no longer trust the user's PC or mobile phone to be honest in their transactions with banks. This paper reviews the current state of the art in protecting PCs from malware and APTs that can modify banking transactions, and identifies their strengths and weaknesses. It then proposes an enhanced USB device based on speech and vision. User trials with a software prototype show that such a device is both user friendly and that users are less susceptible to accepting subtly modified transaction with this device than with other vision only USB devices. Since human factors are usually the weakest point in the security chain, and are often the way that APT actors perform their attacks, the focus of the proposed solution is on improving the usability of existing USB devices. However the device is still not failsafe, and therefore may not be as preferable as Sm@rt TAN-plus that is currently used by many German banks