Columbia University

Displaying 1-40 of 334 results

  • White Papers // Jun 2014

    ParaShares: Finding the Important Basic Blocks in Multithreaded Programs

    Understanding and optimizing multithreaded execution is a significant challenge. Numerous research and industrial tools debug parallel performance by combing through program source or thread traces for pathologies including communication overheads, data dependencies, and load imbalances. This paper takes a new approach: it ignores any underlying pathologies, and focuses instead on...

    Provided By Columbia University

  • White Papers // May 2014

    GASPP: A GPU-Accelerated Stateful Packet Processing Framework

    Graphics Processing Units (GPUs) are a powerful platform for building high-speed network traffic processing applications using low-cost hardware. Existing systems tap the massively parallel architecture of GPUs to speed up certain computationally intensive tasks, such as cryptographic operations and pattern matching. However, they still suffer from significant overheads due to...

    Provided By Columbia University

  • White Papers // Apr 2014

    Benchmarking Methodology for Embedded Scalable Platforms

    Embedded Scalable Platforms (ESP) are a novel generation of platform architectures that yield optimal energy-performance operations while supporting a diversity of embedded application workloads. A companion methodology combines full-system simulation, pre-designed HW/SW interface libraries, high-level synthesis and FPGA prototyping to enable an effective design-space exploration which is driven by the...

    Provided By Columbia University

  • White Papers // Mar 2014

    Trading Functionality for Power within Applications

    When operating systems and hardware manage power and energy, they must be conservative in order to deliver requested resources while maintaining an expected rate of system throughput. Application-level energy management is more flexible, because applications can choose to request fewer resources or expect less performance, effectively trading accuracy or runtime...

    Provided By Columbia University

  • White Papers // Mar 2014

    Unsupervised Anomaly-based Malware Detection using Hardware Features

    Recent works have shown promise in using micro-architectural execution patterns to detect malware programs. These detectors belong to a class of detectors known as signature based detectors as they catch malware by comparing a program's execution pattern (signature) to execution patterns of known malware programs. In this paper, the authors...

    Provided By Columbia University

  • White Papers // Jan 2014

    Efficient Hash Probes on Modern Processors

    Bucketized versions of cuckoo hashing can achieve 95-99% occupancy, without any space overhead for pointers or other structures. However, such methods typically need to consult multiple hash buckets per probe, and have therefore been seen as having worse probe performance than conventional techniques for large tables. The authors consider workloads...

    Provided By Columbia University

  • White Papers // Jan 2014

    Adding a Flow-Oriented Paradigm to Commodity Operating Systems

    The speed of CPUs and memories has historically outstripped I/O, but emerging network and storage technologies promise to invert this relationship. As a result, fundamental assumptions about the role of the operating system in computing systems will have to change. The authors propose an operating and application architecture that removes...

    Provided By Columbia University

  • White Papers // Dec 2013

    On the Effectiveness of Traffic Analysis Against Anonymity Networks Using Flow Records

    The authors investigate the feasibility of mounting a de-anonymization attack against Tor and similar low-latency anonymous communication systems by using NetFlow records. Previous research has shown that adversaries with the ability to eavesdrop in real time at a few internet exchange points can effectively monitor a significant part of the...

    Provided By Columbia University

  • White Papers // Oct 2013

    A Profitable Sub-Prime Loan: Obtaining the Advantages of Composite Order in Prime-Order Bilinear Groups

    Composite-order bilinear groups provide many structural features that have proved useful for both constructing cryptographic primitives and as a technique in security reductions. Despite these convenient features, however, composite-order bilinear groups are less desirable than prime-order bilinear groups for reasons of efficiency. A recent line of paper has therefore focused...

    Provided By Columbia University

  • White Papers // Sep 2013

    Privacy Policy-Driven Mashups

    Mashups are novel content created by extracting and combining data and services from diverse data sources, in an automated manner, using Web services. The Web 2.0 technologies make it easier for individuals to create contents in third party service sites or clouds, and make easier for other third party mashup...

    Provided By Columbia University

  • White Papers // Aug 2013

    CellFlood: Attacking Tor Onion Routers on the Cheap

    In this paper, the authors introduce a new denial-of-service attack against tor onion routers and they study its feasibility and implications. In particular, they exploit a design flaw in the way Tor software builds virtual circuits and demonstrate that an attacker needs only a fraction of the resources required by...

    Provided By Columbia University

  • White Papers // Jul 2013

    Server-Side Code Injection Attacks: A Historical Perspective

    Server-side code injection attacks used to be one of the main culprits for the spread of malware. A vast amount of research has been devoted to the problem of effectively detecting and analyzing these attacks. Common belief seems to be that these attacks are now a marginal threat compared to...

    Provided By Columbia University

  • White Papers // Jun 2013

    Order-Preserving Encryption Secure Beyond One-Wayness

    Semantic-security of individual bits under a ciphertext is fundamental notion in modern cryptography. In this paper, the authors present the first results about this fundamental problem for Order-Preserving Encryption (OPE): \"What plaintext information can be semantically hidden by OPE encryptions?\" While OPE has gained much attention in recent years due...

    Provided By Columbia University

  • White Papers // Jun 2013

    On Finite Block-Length Quantization Distortion

    The authors investigate the upper and lower bounds on the quantization distortions for independent and identically distributed sources in the finite block-length regime. Based on the convex optimization framework of the rate-distortion theory, they derive a lower bound on the quantization distortion under finite block-length, which is shown to be...

    Provided By Columbia University

  • White Papers // Jun 2013

    CloudFence: Data Flow Tracking as a Cloud Service

    The risk of unauthorized private data access is among the primary concerns for users of cloud-based services. For the common setting in which the infrastructure provider and the service provider are different, users have to trust their data to both parties, although they interact solely with the latter. In this...

    Provided By Columbia University

  • White Papers // May 2013

    Computational Decoys for Cloud Security

    Cloud-based applications benefit from the scalability and efficiency offered by server consolidation and shared facilities. However, the shared nature of cloud infrastructures may introduce threats stemming from the co-location and combination of untrusted components, in addition to typical risks due to the inevitable presence of weaknesses in the infrastructure itself....

    Provided By Columbia University

  • White Papers // Apr 2013

    You Can Type, But You Can't Hide: A Stealthy GPU-Based Keylogger

    Keyloggers are a prominent class of malware that harvests sensitive data by recording any typed in information. Keylogger implementations strive to hide their presence using rootkit-like techniques to evade detection by antivirus and other system protections. In this paper, the authors present a new approach for implementing a stealthy keylogger:...

    Provided By Columbia University

  • White Papers // Mar 2013

    Cloudopsy: an Autopsy of Data Flows in the Cloud

    Despite the apparent advantages of cloud computing, the fear of unauthorized exposure of sensitive user data and non-compliance to privacy restrictions impedes its adoption for security-sensitive tasks. For the common setting in which the cloud infrastructure provider and the online service provider are different, end users have to trust the...

    Provided By Columbia University

  • White Papers // Jan 2013

    VBoom: Creating A Virtual Machine Real Estate Boom

    Cloud providers sell identically configured Virtual Machines (VMs) for the same price. Customers purchasing these VMs expect that they perform similarly and are allocated the same amount of virtual resources. In practice, however, the real performance of identically provisioned VMs depends on the underlying hardware, i.e., how the hardware is...

    Provided By Columbia University

  • White Papers // Dec 2012

    Sequential Aggregate Signatures with Short Public Keys: Design, Analysis and Implementation Studies

    The notion of aggregate signature has been motivated by applications and it enables any user to compress different signatures signed by different signers on different messages into a short signature. Sequential aggregate signature, in turn, is a special kind of aggregate signature that only allows a signer to add his...

    Provided By Columbia University

  • White Papers // Dec 2012

    Bait and Snitch: Defending Computer Systems with Decoys

    Threats against computer networks continue to multiply, but existing security solutions are persistently unable to keep pace with these challenges. In this paper the authors present a new paradigm for securing computational resources which they call decoy technology. This technique involves seeding a system with data that appears authentic but...

    Provided By Columbia University

  • White Papers // Nov 2012

    Cross-Layer Enabled Translucent Optical Network With Real-Time Impairment Awareness

    The existing dimensioning strategy for translucent, sub-wavelength switching architectures relies on over-provisioning, and consequently, overuse of costly, power-consuming Optical-Electrical-Optical (O/E/O) regenerators. In addition, due to a variety of external phenomena, many physical layer impairments are time-varying, and hence, can strongly degrade network performance. In this paper, the authors introduce a...

    Provided By Columbia University

  • White Papers // Nov 2012

    Privacy Preserving Revocable Predicate Encryption Revisited

    Predicate Encryption (PE) that provides both the access control of ciphertexts and the privacy of ciphertexts is a new paradigm of public-key encryption. An important application of predicate encryption is a searchable encryption system in a cloud storage, where it enables a client to securely outsource its data to an...

    Provided By Columbia University

  • White Papers // Nov 2012

    Accelerator Memory Reuse in the Dark Silicon Era

    Accelerators integrated on-die with General-Purpose CPUs (GP-CPUs) can yield significant performance and power improvements. Their extensive use, however, is ultimately limited by their area overhead; due to their high degree of specialization, the opportunity cost of investing die real estate on accelerators can become prohibitive, especially for general-purpose architectures. In...

    Provided By Columbia University

  • White Papers // Nov 2012

    Extensible Monitoring with Nagios and Messaging Middleware

    Monitoring is a core function of systems administration, and is primarily a problem of communication - a good monitoring tool communicates with users about problems, and communicates with hosts and software to take remedial action. The better it communicates, the greater the confidence administrators will have in its view of...

    Provided By Columbia University

  • White Papers // Oct 2012

    Aggregating CL-Signatures Revisited: Extended Functionality and Better Efficiency

    Aggregate signature is public-key signature that allows anyone to aggregate different signatures generated by different signers on different messages into a short (called aggregate) signature. The notion has many applications where compressing the signature space is important: in infrastructure: secure routing protocols, in security: compressed certificate chain signature, in signing...

    Provided By Columbia University

  • White Papers // Sep 2012

    CleanOS: Limiting Mobile Data Exposure with Idle Eviction

    Mobile-device theft and loss have reached gigantic proportions. Despite these threats, today's mobile devices are saturated with sensitive information due to operating systems that never securely erase data and applications that hoard it on the vulnerable device for performance or convenience. This paper presents CleanOS, a new Android-based operating system...

    Provided By Columbia University

  • White Papers // Aug 2012

    TimeWarp: Rethinking Timekeeping and Performance Monitoring Mechanisms to Mitigate Side-Channel Attacks

    Over the past two decades, several microarchitectural side channels have been exploited to create sophisticated security attacks. Solutions to this problem have mainly focused on fixing the source of leaks either by limiting the flow of information through the side channel by modifying hardware, or by refactoring vulnerable software to...

    Provided By Columbia University

  • White Papers // Aug 2012

    kGuard: Lightweight Kernel Protection Against Return-to-user Attacks

    Return-to-user (ret2usr) attacks exploit the operating system kernel, enabling local users to hijack privileged execution paths and execute arbitrary code with elevated privileges. Current defenses have proven to be inadequate, as they have been repeatedly circumvented, incur considerable overhead, or rely on extended hypervisors and special hardware features. The authors...

    Provided By Columbia University

  • White Papers // Aug 2012

    Scalable Group Signatures with Revocation

    Group signatures are a central cryptographic primitive, simultaneously supporting accountability and anonymity. They allow users to anonymously sign messages on behalf of a group they are members of. The recent years saw the appearance of several constructions with security proofs in the standard model (i.e., without appealing to the random...

    Provided By Columbia University

  • White Papers // Jul 2012

    Facebook and Privacy: It's Complicated

    The authors measure users' attitudes toward interpersonal privacy concerns on Facebook and measure users' strategies for reconciling their concerns with their desire to share content online. To do this, they recruited 260 Facebook users to install a Facebook application that surveyed their privacy concerns, their friend network compositions, the sensitivity...

    Provided By Columbia University

  • White Papers // Jun 2012

    Privacy-Preserving Social Plugins

    The widespread adoption of social plugins, such as Facebook's Like and Google's +1 buttons, has raised concerns about their implications to user privacy, as they enable social networking services to track a growing part of their members' browsing activity. Existing mitigations in the form of browser extensions can prevent social...

    Provided By Columbia University

  • White Papers // May 2012

    A Robust MDP Approach to Secure Power Control in Cognitive Radio Networks

    Power control plays a key role in realizing reliable and spectrum-efficient communications in a cognitive radio network. In this paper, the authors study secure power control schemes for cognitive radios via a robust Markov Decision Process (MDP) approach. They first use the Discrete Time Markov Chain (DTMC) model to characterize...

    Provided By Columbia University

  • White Papers // May 2012

    CCNxServ: Dynamic Service Scalability in Information-Centric Networks

    Content-centric networks promise to address content networking issues in a better way than today's host-based networking architecture. But content-centric networking does not inherently address the issue of services, particularly service scalability and mobility. The authors present their work on CCNxServ, a system that allows for dynamic service deployment and scalability...

    Provided By Columbia University

  • White Papers // May 2012

    Harmony: Collection and Analysis of Parallel Block Vectors

    Efficient execution of well-parallelized applications is central to performance in the multicore era. Program analysis tools support the hardware and software sides of this effort by exposing relevant features of multithreaded applications. This paper describes parallel block vectors, which uncover previously unseen characteristics of parallel programs. Parallel block vectors provide...

    Provided By Columbia University

  • White Papers // May 2012

    Combining Baiting and User Search Profiling Techniques for Masquerade Detection

    Masquerade attacks are characterized by an adversary stealing a legitimate user's credentials and using them to impersonate the victim and perform malicious activities, such as stealing information. Prior work on masquerade attack detection has focused on profiling legitimate user behavior and detecting abnormal behavior indicative of a masquerade attack. Like...

    Provided By Columbia University

  • White Papers // Apr 2012

    Tolerating Overload Attacks Against Packet Capturing Systems

    Passive network monitoring applications such as intrusion detection systems are susceptible to overloads, which can be induced by traffic spikes or algorithmic singularities triggered by carefully crafted malicious packets. Under overload conditions, the system may consume all the available resources, dropping most of the monitored traffic until the overload condition...

    Provided By Columbia University

  • White Papers // Apr 2012

    ARC: Protecting Against HTTP Parameter Pollution Attacks Using Application Request Caches

    HTTP Parameter Pollution (HPP) vulnerabilities allow attackers to exploit web applications by manipulating the query parameters of the requested URLs. In this paper, the authors present Application Request Cache (ARC), a framework for protecting web applications against HPP exploitation. ARC hosts all benign URL schemas, which act as generators of...

    Provided By Columbia University

  • White Papers // Apr 2012

    Concurrency Attacks

    Just as errors in sequential programs can lead to security exploits, errors in concurrent programs can lead to concurrency attacks. Questions such as whether these attacks are real and what characteristics they have remain largely unknown. In this paper, the authors present a preliminary study of concurrency attacks and the...

    Provided By Columbia University

  • White Papers // Apr 2012

    On the Performance of Flexgrid-Based Optical Networks

    The ever increasing IP traffic volume has finally brought to light the high inefficiency of current wavelength-routed rigid-grid networks in matching the client layer requirements. Such an issue results in the deployment of large-size, expensive and power-consuming IP/MPLS layers to perform the required grooming/aggregation functionality. To deal with this problem,...

    Provided By Columbia University

  • White Papers // Apr 2011

    Performance Evaluation of Resource Allocation Policies for Energy Harvesting Devices

    The authors focus on resource allocation for energy harvesting devices. They analytically and numerically evaluate the performance of algorithms that determine time fair energy allocation in systems with predictable and stochastic energy inputs. To gain insight into the performance of networks of devices, they obtain results for the simple cases...

    Provided By Columbia University

  • White Papers // Apr 2011

    An Integrated Four-Phase Buck Converter Delivering 1A/mm2 With 700ps Controller Delay and Network-on-Chip Load in 45-Nm SOI

    Performance-per-watt is an increasingly important metric for microprocessors as it is now common for the thermal envelope to limit computational performance of an IC. Dynamic Voltage and Frequency Scaling (DVFS) can improve performance-per-watt by reducing wasted power when logic is idling or performing a low priority task. The benefits of...

    Provided By Columbia University

  • White Papers // Nov 2011

    Embedded Processor Virtualization for Broadband Grid Computing

    The authors implemented and evaluated a heterogeneous system architecture that combines a traditional computer cluster with a broadband network of embedded Set-Top Box (STB) devices to provide a distributed computing platform for parallel applications. Their prototype system for broadband grid computing leverages the recent dramatic progress in computational power of...

    Provided By Columbia University

  • White Papers // Apr 2012

    Concurrency Attacks

    Just as errors in sequential programs can lead to security exploits, errors in concurrent programs can lead to concurrency attacks. Questions such as whether these attacks are real and what characteristics they have remain largely unknown. In this paper, the authors present a preliminary study of concurrency attacks and the...

    Provided By Columbia University

  • White Papers // Oct 2011

    Efficient Deterministic Multithreading Through Schedule Relaxation

    Deterministic MultiThreading (DMT) eliminates many pernicious software problems caused by non-determinism. It works by constraining a program to repeat the same thread interleavings, or schedules, when given same input. Despite much recent research, it remains an open challenge to build both deterministic and efficient DMT systems for general programs on...

    Provided By Columbia University

  • White Papers // Apr 2011

    Finding Concurrency Errors in Sequential Code -OS-level, In-Vivo Model Checking of Process Races

    While thread races have drawn huge attention from the research community, little has been done for process races, where multiple - possibly sequential - processes access a shared resource, such as a file, without proper synchronization. The authors present a preliminary study of real process races and show that they...

    Provided By Columbia University

  • White Papers // Sep 2010

    Bypassing Races in Live Applications With Execution Filters

    Deployed multithreaded applications contain many races because these applications are difficult to write, test, and debug. Worse, the number of races in deployed applications may drastically increase due to the rise of multicore hardware and the immaturity of current race detectors. LOOM is a "Live-workaround" system designed to quickly and...

    Provided By Columbia University

  • White Papers // Jul 2010

    Linux-CR: Transparent Application Checkpoint-Restart in Linux

    Application checkpoint-restart is the ability to save the state of a running application so that it can later resume its execution from the time of the checkpoint. Application checkpoint-restart provides many useful benefits including fault recovery, advanced resources sharing, dynamic load balancing and improved service availability. For several years the...

    Provided By Columbia University

  • White Papers // Jun 2010

    KVM for ARM

    As ARM CPUs grow in performance and ubiquity across phones, netbooks, and embedded computers, providing virtualization support for ARM-based devices is increasingly important. The authors present KVM/ARM, a KVM-based virtualization solution for ARM-based devices that can run virtual machines with nearly unmodified operating systems. Because ARM is not virtualizable, KVM/ARM...

    Provided By Columbia University

  • White Papers // Mar 2012

    Fog Computing: Mitigating Insider Data Theft Attacks in the Cloud

    Cloud computing promises to significantly change the way the people use computers and access and store their personal and business information. With these new computing and communications paradigms arise new data security challenges. Existing data protection mechanisms such as encryption have failed in preventing data theft attacks, especially those perpetrated...

    Provided By Columbia University

  • White Papers // Apr 2012

    Lost in Translation: Improving Decoy Documents Via Automated Translation

    Detecting insider attacks continues to prove to be one of the most difficult challenges in securing sensitive data. Decoy information and documents represent a promising approach to detecting malicious masqueraders; however, false positives can interfere with legitimate work and take up user time. The authors propose generating foreign language decoy...

    Provided By Columbia University

  • White Papers // Jan 2012

    A Study of Privacy Setting Errors in an Online Social Network

    Access control policies are notoriously difficult to configure correctly, even people who are professionally trained system administrators experience difficulty with the task. With the increasing popularity of Online Social Networks (OSN) users of all levels are sharing an unprecedented amount of personal information on the Internet. Most OSNs give users...

    Provided By Columbia University

  • White Papers // Sep 2011

    Privacy Enhanced Access Control for Outsourced Data Sharing

    Traditional access control models often assume that the entity enforcing access control policies is also the owner of data and re-sources. This assumption no longer holds when data is outsourced to a third-party storage provider, such as the cloud. Existing access control solutions mainly focus on preserving confidentiality of stored...

    Provided By Columbia University

  • White Papers // Jul 2009

    Source Prefix Filtering in ROFL

    Traditional firewalls have the ability to allow or block traffic based on source address as well as destination address and port number. The authors' original ROFL scheme implements firewalling by layering it on top of routing; however, the original proposal focused just on destination address and port number. Doing route...

    Provided By Columbia University

  • White Papers // Apr 2012

    On the Performance of Flexgrid-Based Optical Networks

    The ever increasing IP traffic volume has finally brought to light the high inefficiency of current wavelength-routed rigid-grid networks in matching the client layer requirements. Such an issue results in the deployment of large-size, expensive and power-consuming IP/MPLS layers to perform the required grooming/aggregation functionality. To deal with this problem,...

    Provided By Columbia University

  • White Papers // Jul 2010

    Hash Tables With Finite Buckets Are Less Resistant to Deletions

    The authors show that when memory is bounded, i.e., buckets are finite, dynamic hash tables that allow insertions and deletions behave significantly worse than their static counterparts that only allow insertions. This behavior differs from previous results in which, when memory is unbounded, the two models behave similarly. They show...

    Provided By Columbia University

  • White Papers // Dec 2009

    CompactDFA: Generic State Machine Compression for Scalable Pattern Matching

    Pattern matching algorithms lie at the core of all contemporary Intrusion Detection Systems (IDS), making it intrinsic to reduce their speed and memory requirements. This paper focuses on the most popular class of pattern-matching algorithms, the Aho-Corasick - like algorithms, which are based on constructing and traversing a Deterministic Finite...

    Provided By Columbia University

  • White Papers // Jan 2012

    An Email Worm Vaccine Architecture

    The authors present an architecture for detecting "Zero-day" worms and viruses in incoming email. Their main idea is to intercept every incoming message, pre-scan it for potentially dangerous attachments, and only deliver messages that are deemed safe. Unlike traditional scanning techniques that rely on some form of pattern matching (signatures),...

    Provided By Columbia University

  • White Papers // May 2012

    A Robust MDP Approach to Secure Power Control in Cognitive Radio Networks

    Power control plays a key role in realizing reliable and spectrum-efficient communications in a cognitive radio network. In this paper, the authors study secure power control schemes for cognitive radios via a robust Markov Decision Process (MDP) approach. They first use the Discrete Time Markov Chain (DTMC) model to characterize...

    Provided By Columbia University

  • White Papers // Apr 2011

    High-Speed Data Transmission in Multi-Layer Deposited Silicon Photonics for Advanced Photonic Networks-on-Chip

    Advanced silicon photonic devices and systems, constructing photonic Networks-on-Chip (NoCs), are slated to be instrumental in enabling new generations of computational parallelism leveraging Chip Multi Processors (CMPs) and memory access systems. These photonic NoCs have the potential to supply an immense amount of bandwidth, while reducing the total energy consumption....

    Provided By Columbia University

  • White Papers // Nov 2012

    Cross-Layer Enabled Translucent Optical Network With Real-Time Impairment Awareness

    The existing dimensioning strategy for translucent, sub-wavelength switching architectures relies on over-provisioning, and consequently, overuse of costly, power-consuming Optical-Electrical-Optical (O/E/O) regenerators. In addition, due to a variety of external phenomena, many physical layer impairments are time-varying, and hence, can strongly degrade network performance. In this paper, the authors introduce a...

    Provided By Columbia University

  • White Papers // May 2012

    Combining Baiting and User Search Profiling Techniques for Masquerade Detection

    Masquerade attacks are characterized by an adversary stealing a legitimate user's credentials and using them to impersonate the victim and perform malicious activities, such as stealing information. Prior work on masquerade attack detection has focused on profiling legitimate user behavior and detecting abnormal behavior indicative of a masquerade attack. Like...

    Provided By Columbia University

  • White Papers // Jun 2012

    Privacy-Preserving Social Plugins

    The widespread adoption of social plugins, such as Facebook's Like and Google's +1 buttons, has raised concerns about their implications to user privacy, as they enable social networking services to track a growing part of their members' browsing activity. Existing mitigations in the form of browser extensions can prevent social...

    Provided By Columbia University

  • White Papers // Aug 2011

    Dead.drop: URL-Based Stealthy Messaging

    The Internet's public character mandates the need for confidential communications in respect to users' right to privacy. Cryptography may not always suffice on its own, as a user can be forced to surrender the key upon discovery of an encrypted message. For that matter, covert channels offer the ability to...

    Provided By Columbia University

  • White Papers // Aug 2011

    IRILD: An Information Retrieval Based Method for Information Leak Detection

    The traditional approach for detecting information leaks is to generate fingerprints of sensitive data, by partitioning and hashing it, and then comparing these fingerprints against outgoing documents. Unfortunately, this approach incurs a high computation cost as every part of document needs to be checked. As a result, it is not...

    Provided By Columbia University

  • White Papers // Jun 2011

    Detecting Traffic Snooping in Tor Using Decoys

    Anonymous communication networks like Tor partially protect the confidentiality of their users' traffic by encrypting all intra-overlay communication. However, when the relayed traffic reaches the boundaries of the overlay network towards its actual destination, the original user traffic is inevitably exposed. At this point, unless end-to-end encryption is used, sensitive...

    Provided By Columbia University

  • White Papers // Jul 2011

    Taint-Exchange: a Generic System for Cross-Process and Cross-Host Taint Tracking

    Dynamic Taint Analysis (DTA) has been heavily used by security researchers for various tasks, including detecting unknown exploits, analyzing malware, preventing information leaks, and many more. Recently, it has been also utilized to track data across processes and hosts to shed light on the interaction of distributed components, but also...

    Provided By Columbia University

  • White Papers // Oct 2011

    A Multilayer Overlay Network Architecture for Enhancing IP Services Availability Against DoS

    Protection against Denial of Service (DoS) attacks is a challenging and ongoing problem. Current overlay-based solutions can transparently filter unauthorized traffic based on user authentication. Such solutions require either pre-established trust or explicit user interaction to operate, which can be circumvented by determined attackers and is not always feasible (e.g.,...

    Provided By Columbia University

  • White Papers // Aug 2009

    Two-Person Control Administration: Preventing Administration Faults Through Duplication

    Modern computing systems are complex and difficult to administer, making them more prone to system administration faults. Faults can occur simply due to mistakes in the process of administering a complex system. These mistakes can make the system insecure or unavailable. Faults can also occur due to a malicious act...

    Provided By Columbia University

  • White Papers // Aug 2012

    TimeWarp: Rethinking Timekeeping and Performance Monitoring Mechanisms to Mitigate Side-Channel Attacks

    Over the past two decades, several microarchitectural side channels have been exploited to create sophisticated security attacks. Solutions to this problem have mainly focused on fixing the source of leaks either by limiting the flow of information through the side channel by modifying hardware, or by refactoring vulnerable software to...

    Provided By Columbia University

  • White Papers // Mar 2011

    Silencing Hardware Backdoors

    Hardware components can contain hidden backdoors, which can be enabled with catastrophic effects or for ill-gotten profit. These backdoors can be inserted by a malicious insider on the design team or a third-party IP provider. In this paper, the authors propose techniques that allow them to build trustworthy hardware systems...

    Provided By Columbia University

  • White Papers // May 2011

    IPv6 Addresses as Content Names in Information-Centric Networking

    Content is quickly beginning to emerge as the core of Internet and networking applications today. Among the most important research issues with content is the problem of addressing and naming content, since a robust and naming-centric networking strategy will enable the building of next-generation Internet architectures that can easily scale...

    Provided By Columbia University

  • White Papers // May 2011

    Dynamic Service Scalability in Information-Centric Networks

    Information- or Content-Centric Networks have gotten a lot of interest recently, particularly due to the promise to address problems inherent in today's host-based networking architecture. But while Information-Centric Networking aims to address the concerns of networking which is evolving in the direction of serving content, it does not inherently address...

    Provided By Columbia University

  • White Papers // Mar 2013

    Cloudopsy: an Autopsy of Data Flows in the Cloud

    Despite the apparent advantages of cloud computing, the fear of unauthorized exposure of sensitive user data and non-compliance to privacy restrictions impedes its adoption for security-sensitive tasks. For the common setting in which the cloud infrastructure provider and the online service provider are different, end users have to trust the...

    Provided By Columbia University

  • White Papers // May 2013

    Computational Decoys for Cloud Security

    Cloud-based applications benefit from the scalability and efficiency offered by server consolidation and shared facilities. However, the shared nature of cloud infrastructures may introduce threats stemming from the co-location and combination of untrusted components, in addition to typical risks due to the inevitable presence of weaknesses in the infrastructure itself....

    Provided By Columbia University

  • White Papers // Jun 2013

    On Finite Block-Length Quantization Distortion

    The authors investigate the upper and lower bounds on the quantization distortions for independent and identically distributed sources in the finite block-length regime. Based on the convex optimization framework of the rate-distortion theory, they derive a lower bound on the quantization distortion under finite block-length, which is shown to be...

    Provided By Columbia University

  • White Papers // Sep 2011

    Uplink Interference Mitigation for OFDMA Femtocell Networks

    Femtocell networks, consisting of a conventional macro cellular deployment and overlaying femtocells, forming a hierarchical cell structure, constitute an attractive solution to improving the macrocell capacity and coverage. However, the inter- and intra-tier interferences in such systems can significantly reduce the capacity and cause an unacceptably high level of outage....

    Provided By Columbia University

  • White Papers // Nov 2012

    Privacy Preserving Revocable Predicate Encryption Revisited

    Predicate Encryption (PE) that provides both the access control of ciphertexts and the privacy of ciphertexts is a new paradigm of public-key encryption. An important application of predicate encryption is a searchable encryption system in a cloud storage, where it enables a client to securely outsource its data to an...

    Provided By Columbia University

  • White Papers // Nov 2012

    Extensible Monitoring with Nagios and Messaging Middleware

    Monitoring is a core function of systems administration, and is primarily a problem of communication - a good monitoring tool communicates with users about problems, and communicates with hosts and software to take remedial action. The better it communicates, the greater the confidence administrators will have in its view of...

    Provided By Columbia University

  • White Papers // Oct 2012

    Aggregating CL-Signatures Revisited: Extended Functionality and Better Efficiency

    Aggregate signature is public-key signature that allows anyone to aggregate different signatures generated by different signers on different messages into a short (called aggregate) signature. The notion has many applications where compressing the signature space is important: in infrastructure: secure routing protocols, in security: compressed certificate chain signature, in signing...

    Provided By Columbia University