Columbia University

Displaying 1-40 of 362 results

  • 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

    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 // 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

    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

    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 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 // Mar 2012

    Toward Practical Private Access to Data Centers Via Parallel ORAM

    Today, accessing maps, pictures, status updates, and other data from online services is de rigueur, but these accesses may leak private information. Previous work proposed using a secure coprocessor at the server to hide all information about user requests via an Oblivious RAM (ORAM) protocol. For this to ever be...

    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 // Mar 2012

    Smashing the Gadgets: Hindering Return-Oriented Programming Using In-Place Code Randomization

    The wide adoption of non-executable page protections in recent versions of popular operating systems has given rise to attacks that employ Return-Oriented Programming (ROP) to achieve arbitrary code execution without the injection of any code. Existing defenses against ROP exploits either require source code or symbolic debugging information, or impose...

    Provided By Columbia University

  • White Papers // Mar 2012

    Predicting the Number of Mobile Subscribers: An Accurate Forecasting System and Its Application

    Forecasting economic quantities can bring high benefits to business planning and operation. To provide accurate forecasts and to investigate the factors behind the trends, the authors present a new prediction system in this paper. Applying it to the Number of Mobile Subscribers (NMS) in the United States, China, and Germany,...

    Provided By Columbia University

  • White Papers // Mar 2012

    Towards a Universal Data Provenance Framework Using Dynamic Instrumentation

    The advantage of collecting data provenance information has driven research on how to extend or modify applications and systems in order to provide it, or the creation of architectures that are built from the ground up with provenance capabilities. In this paper the authors propose a universal data provenance framework,...

    Provided By Columbia University

  • White Papers // Feb 2012

    A System for Generating and Injecting Indistinguishable Network Decoys

    The authors propose a novel trap-based architecture for detecting passive, \"Silent\", attackers who are eavesdropping on enterprise networks. Motivated by the increasing number of incidents where attackers sniff the local network for interesting information, such as credit card numbers, account credentials, and passwords, they introduce a methodology for building a...

    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 // 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 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 // Dec 2011

    Private Search in the Real World

    Encrypted search - performing queries on protected data - has been explored in the past; however, its inherent inefficiency has raised questions of practicality. Here, the authors focus on improving the performance and extending its functionality enough to make it practical. They do this by optimizing the system, and by...

    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 // 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 // Aug 2011

    Improving the Performance of Passive Network Monitoring Applications with Memory Locality Enhancements

    Passive network monitoring is the basis for a multitude of systems that support the robust, efficient, and secure operation of modern computer networks. Emerging network monitoring applications are more demanding in terms of memory and CPU resources due to the increasingly complex analysis operations that are performed on the inspected...

    Provided By Columbia University

  • White Papers // Jul 2011

    REASSURE: A Self-Contained Mechanism for Healing Software Using Rescue Points

    Software errors are frequently responsible for the limited availability of internet services, loss of data, and many security compromises. Self-healing using Rescue Points (RPs) is a mechanism that can be used to recover software from unforeseen errors until a more permanent remedy, like a patch or update, is available. The...

    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 // 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 // Sep 2011

    Measuring the Human Factor of Cyber Security

    In this paper, the authors investigate new methods to measure, quantify and evaluate the security posture of human organizations especially within large corporations. Computer security is not just about technology and systems. It is also about the people that use those systems and how their vulnerable behaviors can lead to...

    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 // 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 // Feb 2011

    Efficient Circuit-Size Independent Public Key Encryption with KDM Security

    Key Dependent Message (KDM) secure encryption is a new area which has attracted much research in recent years. Roughly speaking, a KDM secure scheme w.r.t. a function set F provides security even if one encrypts a key dependent message f(sk) for any f 2 F. The authors present a construction...

    Provided By Columbia University

  • White Papers // Mar 2010

    Cryptography Between Wonderland and Underland

    Cryptography is a very broad field, interdisciplinary in nature, and connected to many other areas (in mathematics, computer science, computer systems and engineering). On the one hand, in theoretical cryptography many new notions have been defined, constructed and improved, especially new protocols and cryptosystems that are very powerful and surprising,...

    Provided By Columbia University

  • White Papers // Dec 2009

    Concise Mercurial Vector Commitments and Independent Zero-Knowledge Sets with Short Proofs

    A (trapdoor) mercurial commitment has two commitment procedures. At committing time, the committer can choose not to commit to a specific message and rather generate a dummy value which it will be able to softly open to any message without being able to completely open it. Hard commitments, on the...

    Provided By Columbia University

  • White Papers // Sep 2009

    Secure Multi-party Computation Minimizing Online Rounds

    Multi-party secure computations are general important procedures to compute any function while keeping the security of private inputs. In this paper the authors ask whether preprocessing can allow low latency (that is, small round) secure multi-party protocols that are Universally-Composable (UC). In particular, they allow any polynomial time pre-processing as...

    Provided By Columbia University

  • White Papers // Dec 2008

    Simple, Black-Box Constructions of Adaptively Secure Protocols

    The authors present a compiler for transforming an Oblivious Transfer (OT) protocol secure against an adaptive semi-honest adversary into one that is secure against an adaptive malicious adversary. Their compiler achieves security in the universal composability framework, assuming access to an ideal commitment functionality, and improves over previous work achieving...

    Provided By Columbia University

  • White Papers // Dec 2007

    Recovering NTRU Secret Key From Inversion Oracles

    The authors consider the NTRU encryption scheme as lately suggested for use, and study the connection between inverting the NTRU primitive (i.e., the one-way function over the message and the blinding information which underlies the NTRU scheme) and recovering the NTRU secret key (universal breaking). They model the inverting algorithms...

    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 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 // 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 // Aug 2008

    A New SIP Event Package For Group Membership Management in Advanced Communications

    Group management is a trendy concept in the Next Generation Network environments. There are many software implementations such as Group List Management Server (GLMS) and in a broader scope: XML Document Management Server (XDMS). These entities are part of the OMA, 3GPP, and IMS specifications. However, in today's dynamic and...

    Provided By Columbia University

  • White Papers // Sep 2008

    VoIP-Based Air Traffic Controller Training

    Extending VoIP beyond the Internet telephony, the authors propose a case study of applying the technology outside of its intended domain, to solve a real-world problem. This paper is an attempt to understand an analog hardwired communication system of the U.S. Federal Aviation Administration (FAA), and effectively translate it into...

    Provided By Columbia University

  • White Papers // Jul 2008

    Session Initiation Protocol (SIP) Server Overload Control: Design and Evaluation

    A Session Initiation Protocol (SIP) server may be overloaded by emergency-induced call volume, "American Idol" style flash crowd effects or denial of service attacks. The SIP server overload problem is interesting especially because the costs of serving or rejecting a SIP session can be similar. For this reason, the built-in...

    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 // 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

  • 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 // 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 // Jun 2011

    Simultaneous Wavelength Conversion of ASK and DPSK Signals Based on Four-Wave-Mixing in Dispersion Engineered Silicon Waveguides

    The authors experimentally demonstrate Four-Wave-Mixing (FWM)-based continuous wavelength conversion of optical Differential-Phase-Shift-Keyed (DPSK) signals with large wavelength conversion ranges as well as simultaneous wavelength conversion of dual-wavelength channels with mixed modulation formats in 1.1-cm-long dispersion-engineered silicon waveguides. They first validate up to 100-nm wavelength conversion range for 10-Gb/s DPSK signals,...

    Provided By Columbia University

  • White Papers // Apr 2011

    DPSK Modulation Using a Microring Modulator

    As Multi-Core Processors (MCPs) continue to scale in size and complexity, the emerging interconnect-bandwidth bottleneck will have to be resolved by technology that transcends traditional electronic interconnects. The lower power dissipation and improved scalability of photonic links over electronic links at high data rates is motivating the development of photonic...

    Provided By Columbia University

  • White Papers // Dec 2010

    Continuously Tunable Wavelength Conversion of Data with Record Probe-Idler Separations in a Silicon Nanowire

    The growing demands for optical communication bandwidth are driving optical communication technologies toward increased wavelength channel density, spectrally-efficient modulation formats, higher symbol rates, as well as increased-density spatial parallelism. In addition to these emerging methods, one can also leverage the bandwidth available beyond the currently utilized C and L ITU...

    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