Columbia University

Displaying 1-40 of 296 results

  • White Papers // Jan 2015

    Lighting Sensitive Display

    Although display devices have been used for decades, they have functioned without taking into account the illumination of their environment. The authors present the concept of a Lighting Sensitive Display (LSD) a display that measures the incident illumination and modifies its content accordingly. Ideal LSD would be able to measure...

    Provided By Columbia University

  • White Papers // Dec 2014

    Movers and Shakers: Kinetic Energy Harvesting for the Internet of Things

    Numerous energy harvesting wireless devices that will serve as building blocks for the Internet of Things (IoT) are currently under development. However, there is still only limited understanding of the properties of various energy sources and their impact on energy harvesting adaptive algorithms. Hence, the authors focus on characterizing the...

    Provided By Columbia University

  • White Papers // Nov 2014

    Malicious-Client Security in Blind Seer: A Scalable Private DBMS

    "The Blind Seer system (Oakland 2014) is an efficient and scalable DBMS that affords both client query privacy and server data protection. It also provides the ability to enforce authorization policies on the system, restricting client's queries while maintaining the privacy of both query and policy. Blind Seer supports a...

    Provided By Columbia University

  • White Papers // Sep 2014

    Pebbles: Fine-Grained Data Management Abstractions for Modern Operating Systems

    Support for fine-grained data management has all but disappeared from modern operating systems such as Android and iOS. Instead, the people must rely on each individual application to manage their data properly - e.g., to delete their emails, documents, and photos in full upon request; to not collect more data...

    Provided By Columbia University

  • 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 // Apr 2014

    Real-Time Power Control for Dynamic Optical Networks - Algorithms and Experimentation

    Core and aggregation optical networks are remarkably static, despite the emerging dynamic capabilities of the individual optical devices. This stems from the inability to address optical impairments in real-time. As a result, tasks such as adding and removing wavelengths take a substantial amount of time, and therefore, optical networks are...

    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

    Tracking Quantiles of Network Data Streams with Dynamic Operations

    Quantiles are very useful in characterizing the data distribution of an evolving dataset in the process of data mining or network monitoring. The method of Stochastic Approximation (SA) tracks quantiles online by incrementally deriving and updating local approximations of the underly distribution function at the quantiles of interest. In this...

    Provided By Columbia University

  • White Papers // Jan 2014

    Throughput Optimization of Wireless Mesh Networks with MIMO Links

    Multiple Input Multiple Output (MIMO) antennas use sophisticated physical layer techniques to provide significant benefits over conventional antenna technology. Multiple independent data streams can be sent over the MIMO antenna elements. MIMO link can also suppress interference from neighboring links as long as the total useful streams and interfering streams...

    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 // Mar 2013

    WiMAX in the Classroom: Designing a Cellular Networking Hands-on Lab

    Wireless networking has recently gained tremendous attention in research and education. Since the concepts taught in wireless courses are difficult to acquire only through lectures, hands-on lab experience is indispensable. While Wi-Fi based networking labs have been introduced before, to the best of the authors' knowledge, labs that use a...

    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

    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

    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

    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 // Feb 2010

    Swift Fox Whitepaper

    For over a decade, wireless sensor networks (WSNs) fostered the development of new applications and trends in the broad areas of mobile and opportunistic computing. Such networks are composed of multiple small, low-cost and low-power, multipurpose sensor nodes that communicate with each other over small distances using the wireless medium...

    Provided By Columbia University

  • White Papers // Jun 2010

    Social Cognitive Conflict Resolution: Contributions Of Domain-General And Domain-Specific Neural Systems

    Cognitive control mechanisms allow individuals to behave adaptively in the face of complex and sometimes conflicting information. Although the neural bases of these control mechanisms have been examined in many contexts, almost no attention has been paid to their role in resolving conflicts between competing social cues, which is surprising...

    Provided By Columbia University

  • White Papers // Dec 2009

    Guide To Career Planning

    Experienced professionals making a career change face particular challenges. Employers tend to be conservative, preferring to hire candidates with prior experience in their sector. Therefore, a career changer must convey in their resume that they understand the new sector they are entering, have relevant transferable skills, and have the enthusiasm...

    Provided By Columbia University

  • White Papers // Dec 2009

    Career Changers - Resume Writing For The Career Changer

    Experienced professionals making a career change face particular challenges. Employers tend to be conservative, preferring to hire candidates with prior experience in their sector. Therefore, a career changer must convey in their resume that they understand the new sector they are entering, have relevant transferable skills, and have the enthusiasm...

    Provided By Columbia University

  • White Papers // Aug 2009

    Delegation And The Regulation Of Finance In The United States Since 1950

    What determines the extent and structure of financial regulation? This question matters for two reasons. First, it matters because, as North and Shirley says "A country's financial institutions significantly determine the extent of new investment and firm entry, and through them, the rate of economic growth, disparity of income distribution,...

    Provided By Columbia University

  • White Papers // Jan 2010

    Characterizing Self-Healing Software Systems

    The introduction of self-healing capabilities to software systems could offer a way to alter the current, unfavorable imbalance in the software security arms race. Consequently, self-healing software systems have emerged as a research area of particular interest in recent years. Motivated by the inability of traditional techniques to guarantee software...

    Provided By Columbia University

  • White Papers // Jan 2010

    Managing Access Control in Large Scale Heterogeneous Networks

    The design principle of maximizing local autonomy except when it conflicts with global robustness has led to a scalable Internet with enormous heterogeneity of both applications and infrastructure. These properties have not been achieved in the mechanisms for specifying and enforcing security policies. The STRONGMAN (for Scalable TRust Of Next...

    Provided By Columbia University

  • White Papers // Jan 2010

    Experimental Analysis of Multi Interface Mobility Management with SIP and MIP

    The authors provide an experimental analysis of MIMM (Multi-Interface Mobility Management) demonstrated in a heterogeneous network involving 802. 1 lb and CDMA access technologies. They have experimented WAN-LAN handoff for real-time service (voice and video) in the test-bed. The subnet handoff managed by MIMM was done seamlessly in this environment...

    Provided By Columbia University

  • White Papers // Apr 2010

    Systems Optimization for Mobility Management

    Wireless network mobility frees the user from location dependence but requires additional mechanism to preserve network connectivity. Mobility events occur when user movement causes one network connection to be replaced by another. A network connection has associated with it properties, for example, network attachment points, network identifiers, and security associations....

    Provided By Columbia University

  • White Papers // Jun 2010

    Dynamic Pricing With Financial Milestones: Feedback-Form Policies

    The authors study a seller that starts with an initial inventory of goods, has a target horizon over which to sell the goods, and is subject to a set of financial milestone constraints on the revenues and sales that need to be achieved at different time points along the sales...

    Provided By Columbia University

  • White Papers // Jan 2011

    Seamless Layer-2 Handoff Using Two Radios in IEEE 802.11 Wireless Networks

    A number of algorithms have been proposed to achieve seamless layer-2 handoff. However, none of them eliminated handoff delay completely although some of them improved handoff time significantly, albeit with change to the infrastructure or 802.11 standard. This paper proposes a handoff algorithm which achieves seamless layer-2 handoff using two...

    Provided By Columbia University

  • White Papers // Jan 2011

    Speculative Execution as an Operating System Service

    Software faults and vulnerabilities continue to present significant obstacles to achieving reliable and secure software. In an effort to overcome these obstacles, systems often incorporate self-monitoring and self-healing functionality. The hypothesis is that internal monitoring is not an effective long-term strategy. However, monitoring mechanisms that are completely external lose the...

    Provided By Columbia University

  • White Papers // Jan 2011

    Linear Approximation of Optimal Attempt Rate in Random Access Networks

    While packet capture has been observed in real implementations of wireless devices randomly accessing shared channels, fair rate control algorithms based on accurate channel models that describe the phenomenon have not been developed. In this paper, using a general physical channel model, the authors develop the equation for the optimal...

    Provided By Columbia University

  • White Papers // Jan 2011

    Throughput and Fairness in CSMA/CA Wireless Networks

    While physical layer capture has been observed in real implementations of wireless devices accessing the channel like 802.11, log-utility fair allocation algorithms based on accurate channel models describing the phenomenon have not been developed. In this paper, using a general physical channel model, the authors develop an allocation algorithm for...

    Provided By Columbia University

  • White Papers // Nov 2009

    The Long-Term Impact Of Job Displacement In Germany During The 1982 Recession On Earnings, Income, And Employment

    The authors show that workers displaced from their stable jobs during mass-layoffs in 1982 recession in Germany suffered permanent earnings losses of 10-15% lasting at least 15 years. These estimates are obtained using data and methodology comparable to similar studies for the United States. Exploiting advantages of the German data,...

    Provided By Columbia University

  • White Papers // Nov 2009

    The Effects Of Unemployment Insurance On Labor Supply And Search Outcomes: Regression Discontinuity Estimates From Germany

    This paper evaluates the impact of large changes in the duration of Unemployment Insurance (UI) in different economic environments on labor supply, job matches, and search behavior. The authors show that differences in eligibility thresholds by exact age give rise to a valid regression discontinuity design, which they implement using...

    Provided By Columbia University

  • White Papers // Jan 2010

    Simple Analytics Of The Government Expenditure Multiplier

    This paper explains the key factors that determine the effectiveness of government purchases as a means of increasing output and employment in New Keynesian models, through a series of simple examples that can be solved analytically. Delays in the adjustment of prices or wages can allow for larger multipliers than...

    Provided By Columbia University

  • White Papers // Feb 2010

    Optimal Target Criteria For Stabilization Policy

    This paper considers a general class of nonlinear rational-expectations models in which policymakers seek to maximize an objective function that may be household expected utility. The authors show how to derive a target criterion that is: consistent with the model's structural equations, strong enough to imply a unique equilibrium, and...

    Provided By Columbia University

  • White Papers // Aug 2009

    Credit Spreads And Monetary Policy

    The authors consider the desirability of modifying a standard Taylor rule for a central bank's interest-rate policy to incorporate either an adjustment for changes in interest-rate spreads or a response to variations in the aggregate volume of credit. They consider the consequences of such adjustments for the way in which...

    Provided By Columbia University

  • White Papers // Aug 2009

    Resolving Conflicting Preferences In School Choice: The "Boston" Mechanism Reconsidered

    The Boston mechanism is among the most popular school choice procedures in use. Yet, the mechanism has been criticized for its poor incentive and welfare performances, which led the Boston Public Schools to recently replace it with Gale and Shapley's deferred acceptance algorithm (henceforth, DA). The DA elicits truthful revelation...

    Provided By Columbia University

  • White Papers // Aug 2009

    Preferences And Equilibrium In Monopoly And Duopoly

    This paper takes the new approach of using a copula to characterize consumer preferences in a discrete choice model of product differentiation, and applies it to the economics of monopoly and duopoly. The comparative statics of demand strength and preference diversity, both properties of the marginal distribution of values for...

    Provided By Columbia University

  • White Papers // Oct 2009

    Son Preference, Sex Selection And Economic Development: Theory And Evidence From South Korea

    Motivated by high and rising sex ratios in countries such as India and China, the authors formulate a theoretical framework for analyzing the impact of economic development on parental sex choice when sons are culturally prized and children provide old age support. Two key assumptions drive the model. First, the...

    Provided By Columbia University

  • White Papers // Mar 2010

    Imperfect Information And Aggregate Supply

    This paper surveys the research in the past decade on imperfect information models of aggregate supply and the Phillips curve. This new work has emphasized that information is dispersed and disseminates slowly across a population of agents who strategically interact in their use of information. The authors discuss the foundations...

    Provided By Columbia University

  • White Papers // Mar 2010

    Interpreting The Unconventional U.S. Monetary Policy Of 2007-09

    This paper reviews the unconventional U.S. monetary policy responses to the financial and real crises of 2007-09, divided into three groups: interest rate policy, quantitative policy, and credit policy. To interpret interest rate policy, it compares the Federal Reserve's actions with the literature on optimal policy in a liquidity trap....

    Provided By Columbia University

  • White Papers // Mar 2010

    Matching With Trade-Offs: Revealed Preferences Over Competing Characteristics

    The authors investigate in this paper the theory and econometrics of optimal matching's with competing criteria. The surplus from a marriage match, for instance, may depend both on the incomes and on the educations of the partners, as well as on characteristics that the analyst does not observe. The social...

    Provided By Columbia University

  • White Papers // May 2010

    Higher Order Improvements For Approximate Estimators

    Many modern estimation methods in econometrics approximate an objective function, through simulation or discretization for instance. The resulting "Approximate" estimator is often biased; and it always incurs an efficiency loss. The authors here propose three methods to improve the properties of such approximate estimators at a low computational cost. The...

    Provided By Columbia University

  • White Papers // Apr 2010

    Challenges for the Location-Aware Web

    The Web is on its way to becoming a location-aware information system. This transition causes some technical and policy challenges in terms of both design and coordination with existing approaches in this area. In this paper the authors propose that managing the transition to location-awareness (and some other aspects) requires...

    Provided By Columbia University

  • White Papers // Jan 2011

    LoST: A Protocol for Mapping Geographic Locations to Public Safety Answering Points

    Public Safety Answering Points (PSAPs) serve limited geographic areas, so emergency callers must be directed to the most appropriate PSAP. As part of the overall Internet Engineering Task Force (IETF) emergency services architecture, the authors have developed a new protocol, LoST (Location-to-Service Translation), that allows end systems and VoIP proxies...

    Provided By Columbia University

  • White Papers // Sep 2009

    TagLearner: A P2P Classifier Learning System From Collaboratively Tagged Text Documents

    The amount of text data on the Internet is growing at a very fast rate. Online text repositories for news agencies, digital libraries and other organizations currently store gigaand tera-bytes of data. Large amounts of unstructured text poses a serious challenge for data mining and knowledge extraction. End user participation...

    Provided By Columbia University

  • White Papers // Jan 2011

    Balancing Uplink and Downlink Delay of VoIP Traffic in WLANs Using Adaptive Priority Control (APC)

    In IEEE 802.11 wireless networks, the downlink delay rises as the number of VoIP nodes increases while the uplink delay remains small due to the same chance of media access between nodes and the Access Point (AP). This degrades the capacity and QoS of VoIP significantly. Therefore, they introduce Adaptive...

    Provided By Columbia University

  • White Papers // Dec 2009

    Network Bandwidth Denial of Service (DoS)

    Network bandwidth Denial of Service (DoS) attacks seek to consume the available bandwidth or router resources at or near a target host or network, such that legitimate traffic cannot reach its destination. The primary means for achieving this goal by sending large traffic volumes (packet floods) that do not respect...

    Provided By Columbia University

  • White Papers // Nov 2010

    Evaluation of a Spyware Detection System Using Thin Client Computing

    In previous work, the authors introduced a bait injection system designed to delude and detect crimeware by forcing it to reveal itself during the exploitation of monitored information. Although effective as a technique, the original system was practically limited, as it was implemented in a personal VM environment. In this...

    Provided By Columbia University

  • White Papers // Aug 2009

    Deny-by-Default Distributed Security Policy Enforcement in Mobile Ad Hoc Networks

    Mobile Ad-hoc Networks (MANETs) are increasingly employed in tactical military and civil rapid-deployment networks, including emergency rescue operations and ad hoc disaster-relief networks. However, this flexibility of MANETs comes at a price, when compared to wired and base station-based wireless networks: MANETs are susceptible to both insider and outsider attacks....

    Provided By Columbia University

  • White Papers // Aug 2009

    Monitoring Technologies for Mitigating Insider Threats

    The annual Computer Crime and Security Survey for 2008 surveyed 522 security employees from US corporations and government agencies, finding that insider incidents were cited by 44 percent of respondents, nearly as high as the 49 percent that encountered a conventional virus in the previous year. In general, there is...

    Provided By Columbia University

  • White Papers // Aug 2010

    Securing MANET Multicast Using DIPLOMA

    Multicast traffic, such as live audio/video streaming, is an important application for Mobile Ad Hoc Networks (MANETs), including those used by militaries and disaster recovery teams. The open nature of multicast, where any receiver can join a multicast group, and any sender can send to a multicast group, makes it...

    Provided By Columbia University

  • White Papers // Jun 2010

    An Analysis of Rogue AV Campaigns

    Rogue antivirus software has recently received extensive attention, justified by the diffusion and efficacy of its propagation. The authors present a longitudinal analysis of the rogue antivirus threat ecosystem, focusing on the structure and dynamics of this threat and its economics. To that end, the authors compiled and mined a...

    Provided By Columbia University

  • White Papers // Nov 2010

    Towards a Forensic Analysis for Multimedia Communication Services

    No matter how robust the employed security mechanisms are malicious users or attackers will always find a way to bypass them. In addition, National Institute of Security and Technology mentions "In conjunction with appropriate tools & procedures, audit trail can assist in detecting security violation and flaws in applications". Until...

    Provided By Columbia University

  • White Papers // Jan 2011

    TAPI: Transactions for Accessing Public Infrastructure

    This paper describes TAPI, an offline scheme intended for general Internet-based micropayments. TAPI, which extends and combines concepts from the KeyNote Microchecks and OTPCoins architectures, encodes risk management rules in bank-issued users' credentials which are in turn used to acquire small valued payment tokens. The scheme has very low transaction...

    Provided By Columbia University

  • White Papers // Jan 2011

    A Pay-Per-Use DoS Protection Mechanism for the Web

    Internet service providers have resisted deploying Denial-of-Service (DoS) protection mechanisms despite numerous research results in the area. This is so primarily because ISPs cannot directly charge users for the use of such mechanisms, discouraging investment in the necessary infrastructure and operational support. The authors describe a pay-per-use system that provides...

    Provided By Columbia University

  • White Papers // Jan 2011

    Design and Implementation of Virtual Private Services

    Large scale distributed applications such as electronic commerce and online marketplaces combine network access with multiple storage and computational elements. The distributed responsibility for resource control creates new security and privacy issues, which are exacerbated by the complexity of the operating environment. In order to handle policies at multiple locations,...

    Provided By Columbia University