Darmstadt University of Technology

Displaying 1-34 of 34 results

  • White Papers // Nov 2013

    Notions of Black-Box Reductions

    Reductions are the common technique to prove security of cryptographic constructions based on a primitive. They take an allegedly successful adversary against the construction and turn it into a successful adversary against the underlying primitive. To a large extent, these reductions are black-box in the sense that they consider the...

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2013

    Reset Indifferentiability and its Consequences

    The authors complement these latter works in several ways. First, they show that any simulator satisfying the reset in-differentiability notion must be stateless and pseudo deterministic. Using this characterization they show that, with respect to reset in-differentiability, two ideal models are either equivalent or incomparable, that is, a model cannot...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2013

    Ideal-Cipher (Ir)reducibility for Blockcipher-Based Hash Functions

    The researcher (Crypto 1993) assessed 64 possible ways to construct a compression function out of a block-cipher. They conjectured that 12 out of these 64 so-called PGV constructions achieve optimal security bounds for collision resistance and pre-image resistance. This was proven by researcher (Journal of Cryptology, 2010), if one assumes...

    Provided By Darmstadt University of Technology

  • White Papers // May 2013

    Salvaging Indifferentiability in a Multi-stage Setting

    In this paper the authors introduce a framework to work with the in-differentiability notion in multi-stage scenarios. The researchers recently presented schemes which are provably secure in the Random-Oracle Model (ROM), but easily broken if the random oracle is replaced by typical in-differentiable hash constructions such as chop-MD or pre...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2013

    Less is More: Relaxed Yet Composable Security Notions for Key Exchange

    Although they do not suffer from clear attacks, various key agreement protocols (for example that used within the TLS protocol) are deemed as insecure by existing security models for key exchange. The reason is that the derived keys are used within the key exchange step, violating the usual key indistinguishability...

    Provided By Darmstadt University of Technology

  • White Papers // Nov 2012

    On the Semantic Security of Functional Encryption Schemes

    Functional Encryption (FE) is a powerful cryptographic primitive that generalizes many asymmetric encryption systems proposed in recent years. Syntax and security definitions for general FE were recently proposed by Boneh, Sahai, and Waters (BSW) (TCC 2011) and independently by O'Neill. In this paper, the authors revisit these definitions, identify several...

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2012

    Domain-Specific Pseudonymous Signatures for the German Identity Card

    The restricted identification protocol for the new German identity card basically provides a method to use pseudonyms such that they can be linked by individual service providers, but not across different service providers (even not malicious ones). The protocol can be augmented to allow also for signatures under the pseudonyms....

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2012

    Unconditionally-Secure Universally Composable Password-Based Key-Exchange based on One-Time Memory Tokens

    The authors continue the recent trend in cryptography to study protocol design in presence of tamper-proof hardware tokens. They present a very efficient protocol for password-based authenticated key exchange based on the weak model of one-time memory tokens, recently introduced by Goldwasser et al. (Crypto 2008). Their protocol only requires...

    Provided By Darmstadt University of Technology

  • White Papers // Aug 2012

    Non-Interactive Public Accountability for Sanitizable Signatures

    Sanitizable signatures enable a designated party to modify signed documents in a controlled way, while the derived signature still verifies. In this paper, the authors introduce the notion of non-interactive and public accountability. It allows a third party to determine whether a message-signature pair was issued by the signer or...

    Provided By Darmstadt University of Technology

  • White Papers // Jul 2012

    Comparative Analysis of Dynamic Task Mapping Heuristics in Heterogeneous NoC-Based MPSoCs

    Dynamic mapping heuristics can cope with dynamic application scenarios by allocating tasks to cores of an MPSoC during runtime. In this paper, the authors compare eight heuristics in terms of the response time of application tasks - that is, the time between the issuing of a task and the time...

    Provided By Darmstadt University of Technology

  • White Papers // Jul 2012

    On the Joint Security of Signature and Encryption Schemes under Randomness Reuse: Efficiency and Security Amplification

    The authors extend the work of Bellare, Boldyreva and Staddon on the systematic analysis of randomness reuse to construct multi-recipient encryption schemes to the case where randomness is reused across different cryptographic primitives. They find that through the additional binding introduced through randomness reuse, one can actually obtain a security...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2012

    Hash Combiners for Second Pre-Image Resistance, Target Collision Resistance and Pre-Image Resistance have Long Output

    A (k; l) hash-function combiner for property P is a construction that, given access to l hash functions, yields a single cryptographic hash function which has property P as long as at least k out of the l hash functions have that property. Hash function combiners are used to hedge...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2012

    Provably Secure Distance-Bounding: An Analysis of Prominent Protocols

    Distance-bounding protocols aim to prevent man-in-the-middle attacks by measuring response times. At ISC 2011, Durholz et al. formalized the four attacks such protocols typically address: mafia attacks, where the adversary must impersonate to a verifier in the presence of an honest prover, terrorist attacks, where the adversary gets limited offline...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2011

    A Formal Approach to Distance-Bounding RFID Protocols

    Distance-Bounding identification protocols aim at impeding man-in-the-middle attacks by measuring response times. There are three kinds of attacks such protocols could address: mafia attacks where the adversary relays communication between honest prover and honest verifier in different sessions; Terrorist attacks where the adversary gets limited active support from the prover...

    Provided By Darmstadt University of Technology

  • White Papers // May 2011

    City Mesh - Resilient First Responder Communication

    Communication between first responders is vital to the success of large scale disaster management. But communication technologies used by first responders today do not scale well due to heterogeneity, point-to-point connections, and centralized communication structures. As the popularity of devices equipped with Wi-Fi grows, the number of Access Points (APs)...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2011

    Secure Set Intersection With Untrusted Hardware Tokens

    Secure set intersection protocols are the core building block for a manifold of privacy-preserving applications. In their basic form, secure protocols for set intersection follow from general feasibility results for secure two-party computation. However, efficiency requirements for practical deployment have recently incited efforts to design dedicated protocols which are significantly...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2011

    Flexible Wormhole-Switched Network-on-Chip With Two-Level Priority Data Delivery Service

    A synchronous network-on-chip using wormhole packet switching and supporting guaranteed-completion best-effort with Low-Priority (LP) and High-Priority (HP) wormhole packet delivery service is presented in this paper. Both the proposed LP and HP message services deliver a good quality of service in term of lossless packet completion and in-order message data...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2011

    Survey on Location Privacy in Pervasive Computing

    The goal of ubiquitous computing research is re ne devices to the point where their use is transparent. For many applications with mobile devices, transparent operation requires that the device be location aware. Unfortunately, the location of an individual can be used to infer highly private information. Hence, these devices...

    Provided By Darmstadt University of Technology

  • White Papers // Oct 2010

    Numerical Explorations Of The Ngai-Pissarides Model Of Growth And Structural Change

    In this paper, the authors specialize the Ngai-Pissarides model of growth and structural change to the case of three sectors, representing the primary (agriculture, mining), secondary (construction, manufacturing) and tertiary (services) sectors. On that basis they explore the dynamic properties of the model along the transition path to the steady-state...

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2010

    Random Oracles With(out) Programmability

    In this paper, the authors investigate the Random Oracle Model (ROM) feature known as programmability, which allows security reductions in the ROM to dynamically choose the range points of an ideal hash function. This property is interesting for at least two reasons: because of its seeming artificiality (no standard model...

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2010

    Security and Privacy in Online Social Networks

    In this paper, the authors deal with security in Online Social Networks (OSN). It introduces Online Social Networks as the digital representations of relationships, which their users entertain in the physical world. Social Network Providers (SNP), commonly commercial entities that offer Social Networking Services (SNS), the access to the OSN,...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2010

    Detecting Sensitive Information from Textual Documents: An Information-Theoretic Approach

    Whenever a document containing sensitive information needs to be made public, privacy-preserving measures should be implemented. Document sanitization aims at detecting sensitive pieces of information in text, which are removed or hidden prior publication. Even though methods detecting sensitive structured information like e-mails, dates or social security numbers, or domain...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2010

    Unlinkability of Sanitizable Signatures

    Sanitizable signatures allow a designated party, called the sanitizer, to modify parts of signed data such that the immutable parts can still be verified with respect to the original signer. The researcher (ES- ORICS 2005) discusses five security properties for such signature schemes: unforgeability, immutability, privacy, transparency and accountability. These...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2010

    Instruction Set Simulator for MPSoCs Based on NoCs and MIPS Processors

    Even though Multi-Processor System-on-Chip (MPSoC) is a hot topic for a decade, Instruction Set Simulators (ISSs) for it are still scarce. Data exchange among processors and synchronization directives are some of the most required characteristics that ISSs for MPSoCs should supply to really make use of the processing power provided...

    Provided By Darmstadt University of Technology

  • White Papers // Feb 2010

    On the Impossibility of Three-Move Blind Signature Schemes

    The authors investigate the possibility to prove security of the well-known blind signature schemes by the researchers in the standard model, i.e., without random oracles. They subsume these schemes under a more general class of blind signature schemes and show that finding security proofs for these schemes via black-box reductions...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2010

    Development of XML-Based Tools to Support User Interaction With Algorithm Visualizations

    An increasing body of evidence suggests Algorithm Visualization (AV) is effective only in conjunction with other techniques that force a degree of user interaction beyond the mere "Watching" of an algorithm. One of the difficulties faced by instructors who design visualizations to use in their teaching lies in the time...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2009

    Delayed-Key Message Authentication for Streams

    The authors consider message authentication codes for streams where the key becomes known only at the end of the stream. This usually happens in key-exchange protocols like SSL and TLS where the exchange phase concludes by sending a MAC for the previous transcript and the newly derived key. SSL and...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2009

    Comparing Monetary Policy Rules In A Small Open Economy Framework: An Empirical Analysis Using Bayesian Techniques

    This paper examines the role of exchange rate changes in the monetary policy for the Euro Area. Moreover, it compares different Taylor-type policy rules with respect to the numerical results as well as the impulse responses to exogenous shocks and the ?t of the different data model specifications when using...

    Provided By Darmstadt University of Technology

  • White Papers // Jul 2009

    Cooperative Transmission for Wireless Relay Networks Using Limited Feedback

    To achieve the available performance gains in half-duplex wireless relay networks, several cooperative schemes have been earlier proposed using either distributed space-time coding or distributed beamforming for the transmitter without and with Channel State Information (CSI), respectively. However, these schemes typically have rather high implementation and/or decoding complexities, especially when...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2009

    Benchmarking of Message-Oriented Middleware

    Message-Oriented Middleware (MOM) is increasingly used as enabling technology for modern event-driven applications typically based on publish/subscribe (pub/sub) communication. Many of these applications are designed for maximum scalability and flexibility and as such, they pose some serious performance issues for the underlying pub/sub middleware. Additionally, software designers face a new...

    Provided By Darmstadt University of Technology

  • White Papers // May 2009

    Does Growth Cause Structural Change, Or Is It The Other Way Round? A Dynamic Panel Data Analyses For Seven OECD Countries

    In economic development, structural change among the three main sectors of an economy accompanies with aggregate economic growth. Nevertheless the question whether economic growth causes structural change or change in the economic structure causes aggregate growth is still unanswered. To shed some more light on this issue, this paper examines...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2009

    Ad Hoc Collaboration and Information Services Using Information Clouds

    Future wireless communication environments offer many possibilities for new services. Users will not be satisfied with simply being connected, but they will require useful services built on top of the wireless networks. iClouds is an architecture which offers spontaneous mobile user interaction, collaboration, and transparent data exchange in mobile ad...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2008

    Security of Blind Signatures Under Aborts

    The authors explore the security of blind signatures under aborts where the user or the signer may stop the interactive signature issue protocol prematurely. Several works on blind signatures discuss security only in regard of completed executions and usually do not impose strong security requirements in case of aborts. One...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2008

    Security of Sanitizable Signatures Revisited

    Sanitizable signature schemes, as defined by the researcher, allow a signer to partly delegate signing rights to an-other party, called the sanitizer. That is, the sanitizer is able to modify a predetermined part of the original message such that the integrity and authenticity of the unchanged part is still verifiable....

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2012

    Domain-Specific Pseudonymous Signatures for the German Identity Card

    The restricted identification protocol for the new German identity card basically provides a method to use pseudonyms such that they can be linked by individual service providers, but not across different service providers (even not malicious ones). The protocol can be augmented to allow also for signatures under the pseudonyms....

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2012

    Unconditionally-Secure Universally Composable Password-Based Key-Exchange based on One-Time Memory Tokens

    The authors continue the recent trend in cryptography to study protocol design in presence of tamper-proof hardware tokens. They present a very efficient protocol for password-based authenticated key exchange based on the weak model of one-time memory tokens, recently introduced by Goldwasser et al. (Crypto 2008). Their protocol only requires...

    Provided By Darmstadt University of Technology

  • White Papers // Nov 2012

    On the Semantic Security of Functional Encryption Schemes

    Functional Encryption (FE) is a powerful cryptographic primitive that generalizes many asymmetric encryption systems proposed in recent years. Syntax and security definitions for general FE were recently proposed by Boneh, Sahai, and Waters (BSW) (TCC 2011) and independently by O'Neill. In this paper, the authors revisit these definitions, identify several...

    Provided By Darmstadt University of Technology

  • White Papers // Jul 2012

    On the Joint Security of Signature and Encryption Schemes under Randomness Reuse: Efficiency and Security Amplification

    The authors extend the work of Bellare, Boldyreva and Staddon on the systematic analysis of randomness reuse to construct multi-recipient encryption schemes to the case where randomness is reused across different cryptographic primitives. They find that through the additional binding introduced through randomness reuse, one can actually obtain a security...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2012

    Hash Combiners for Second Pre-Image Resistance, Target Collision Resistance and Pre-Image Resistance have Long Output

    A (k; l) hash-function combiner for property P is a construction that, given access to l hash functions, yields a single cryptographic hash function which has property P as long as at least k out of the l hash functions have that property. Hash function combiners are used to hedge...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2013

    Less is More: Relaxed Yet Composable Security Notions for Key Exchange

    Although they do not suffer from clear attacks, various key agreement protocols (for example that used within the TLS protocol) are deemed as insecure by existing security models for key exchange. The reason is that the derived keys are used within the key exchange step, violating the usual key indistinguishability...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2009

    Ad Hoc Collaboration and Information Services Using Information Clouds

    Future wireless communication environments offer many possibilities for new services. Users will not be satisfied with simply being connected, but they will require useful services built on top of the wireless networks. iClouds is an architecture which offers spontaneous mobile user interaction, collaboration, and transparent data exchange in mobile ad...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2009

    Benchmarking of Message-Oriented Middleware

    Message-Oriented Middleware (MOM) is increasingly used as enabling technology for modern event-driven applications typically based on publish/subscribe (pub/sub) communication. Many of these applications are designed for maximum scalability and flexibility and as such, they pose some serious performance issues for the underlying pub/sub middleware. Additionally, software designers face a new...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2010

    Development of XML-Based Tools to Support User Interaction With Algorithm Visualizations

    An increasing body of evidence suggests Algorithm Visualization (AV) is effective only in conjunction with other techniques that force a degree of user interaction beyond the mere "Watching" of an algorithm. One of the difficulties faced by instructors who design visualizations to use in their teaching lies in the time...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2009

    Comparing Monetary Policy Rules In A Small Open Economy Framework: An Empirical Analysis Using Bayesian Techniques

    This paper examines the role of exchange rate changes in the monetary policy for the Euro Area. Moreover, it compares different Taylor-type policy rules with respect to the numerical results as well as the impulse responses to exogenous shocks and the ?t of the different data model specifications when using...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2011

    Survey on Location Privacy in Pervasive Computing

    The goal of ubiquitous computing research is re ne devices to the point where their use is transparent. For many applications with mobile devices, transparent operation requires that the device be location aware. Unfortunately, the location of an individual can be used to infer highly private information. Hence, these devices...

    Provided By Darmstadt University of Technology

  • White Papers // Jul 2009

    Cooperative Transmission for Wireless Relay Networks Using Limited Feedback

    To achieve the available performance gains in half-duplex wireless relay networks, several cooperative schemes have been earlier proposed using either distributed space-time coding or distributed beamforming for the transmitter without and with Channel State Information (CSI), respectively. However, these schemes typically have rather high implementation and/or decoding complexities, especially when...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2011

    Flexible Wormhole-Switched Network-on-Chip With Two-Level Priority Data Delivery Service

    A synchronous network-on-chip using wormhole packet switching and supporting guaranteed-completion best-effort with Low-Priority (LP) and High-Priority (HP) wormhole packet delivery service is presented in this paper. Both the proposed LP and HP message services deliver a good quality of service in term of lossless packet completion and in-order message data...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2011

    A Formal Approach to Distance-Bounding RFID Protocols

    Distance-Bounding identification protocols aim at impeding man-in-the-middle attacks by measuring response times. There are three kinds of attacks such protocols could address: mafia attacks where the adversary relays communication between honest prover and honest verifier in different sessions; Terrorist attacks where the adversary gets limited active support from the prover...

    Provided By Darmstadt University of Technology

  • White Papers // May 2009

    Does Growth Cause Structural Change, Or Is It The Other Way Round? A Dynamic Panel Data Analyses For Seven OECD Countries

    In economic development, structural change among the three main sectors of an economy accompanies with aggregate economic growth. Nevertheless the question whether economic growth causes structural change or change in the economic structure causes aggregate growth is still unanswered. To shed some more light on this issue, this paper examines...

    Provided By Darmstadt University of Technology

  • White Papers // Oct 2010

    Numerical Explorations Of The Ngai-Pissarides Model Of Growth And Structural Change

    In this paper, the authors specialize the Ngai-Pissarides model of growth and structural change to the case of three sectors, representing the primary (agriculture, mining), secondary (construction, manufacturing) and tertiary (services) sectors. On that basis they explore the dynamic properties of the model along the transition path to the steady-state...

    Provided By Darmstadt University of Technology

  • White Papers // May 2011

    City Mesh - Resilient First Responder Communication

    Communication between first responders is vital to the success of large scale disaster management. But communication technologies used by first responders today do not scale well due to heterogeneity, point-to-point connections, and centralized communication structures. As the popularity of devices equipped with Wi-Fi grows, the number of Access Points (APs)...

    Provided By Darmstadt University of Technology

  • White Papers // Jan 2011

    Secure Set Intersection With Untrusted Hardware Tokens

    Secure set intersection protocols are the core building block for a manifold of privacy-preserving applications. In their basic form, secure protocols for set intersection follow from general feasibility results for secure two-party computation. However, efficiency requirements for practical deployment have recently incited efforts to design dedicated protocols which are significantly...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2012

    Provably Secure Distance-Bounding: An Analysis of Prominent Protocols

    Distance-bounding protocols aim to prevent man-in-the-middle attacks by measuring response times. At ISC 2011, Durholz et al. formalized the four attacks such protocols typically address: mafia attacks, where the adversary must impersonate to a verifier in the presence of an honest prover, terrorist attacks, where the adversary gets limited offline...

    Provided By Darmstadt University of Technology

  • White Papers // Aug 2012

    Non-Interactive Public Accountability for Sanitizable Signatures

    Sanitizable signatures enable a designated party to modify signed documents in a controlled way, while the derived signature still verifies. In this paper, the authors introduce the notion of non-interactive and public accountability. It allows a third party to determine whether a message-signature pair was issued by the signer or...

    Provided By Darmstadt University of Technology

  • White Papers // Jun 2013

    Ideal-Cipher (Ir)reducibility for Blockcipher-Based Hash Functions

    The researcher (Crypto 1993) assessed 64 possible ways to construct a compression function out of a block-cipher. They conjectured that 12 out of these 64 so-called PGV constructions achieve optimal security bounds for collision resistance and pre-image resistance. This was proven by researcher (Journal of Cryptology, 2010), if one assumes...

    Provided By Darmstadt University of Technology

  • White Papers // May 2013

    Salvaging Indifferentiability in a Multi-stage Setting

    In this paper the authors introduce a framework to work with the in-differentiability notion in multi-stage scenarios. The researchers recently presented schemes which are provably secure in the Random-Oracle Model (ROM), but easily broken if the random oracle is replaced by typical in-differentiable hash constructions such as chop-MD or pre...

    Provided By Darmstadt University of Technology

  • White Papers // Jul 2012

    Comparative Analysis of Dynamic Task Mapping Heuristics in Heterogeneous NoC-Based MPSoCs

    Dynamic mapping heuristics can cope with dynamic application scenarios by allocating tasks to cores of an MPSoC during runtime. In this paper, the authors compare eight heuristics in terms of the response time of application tasks - that is, the time between the issuing of a task and the time...

    Provided By Darmstadt University of Technology

  • White Papers // Nov 2013

    Notions of Black-Box Reductions

    Reductions are the common technique to prove security of cryptographic constructions based on a primitive. They take an allegedly successful adversary against the construction and turn it into a successful adversary against the underlying primitive. To a large extent, these reductions are black-box in the sense that they consider the...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2010

    Instruction Set Simulator for MPSoCs Based on NoCs and MIPS Processors

    Even though Multi-Processor System-on-Chip (MPSoC) is a hot topic for a decade, Instruction Set Simulators (ISSs) for it are still scarce. Data exchange among processors and synchronization directives are some of the most required characteristics that ISSs for MPSoCs should supply to really make use of the processing power provided...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2010

    Detecting Sensitive Information from Textual Documents: An Information-Theoretic Approach

    Whenever a document containing sensitive information needs to be made public, privacy-preserving measures should be implemented. Document sanitization aims at detecting sensitive pieces of information in text, which are removed or hidden prior publication. Even though methods detecting sensitive structured information like e-mails, dates or social security numbers, or domain...

    Provided By Darmstadt University of Technology

  • White Papers // Mar 2010

    Unlinkability of Sanitizable Signatures

    Sanitizable signatures allow a designated party, called the sanitizer, to modify parts of signed data such that the immutable parts can still be verified with respect to the original signer. The researcher (ES- ORICS 2005) discusses five security properties for such signature schemes: unforgeability, immutability, privacy, transparency and accountability. These...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2009

    Delayed-Key Message Authentication for Streams

    The authors consider message authentication codes for streams where the key becomes known only at the end of the stream. This usually happens in key-exchange protocols like SSL and TLS where the exchange phase concludes by sending a MAC for the previous transcript and the newly derived key. SSL and...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2008

    Security of Blind Signatures Under Aborts

    The authors explore the security of blind signatures under aborts where the user or the signer may stop the interactive signature issue protocol prematurely. Several works on blind signatures discuss security only in regard of completed executions and usually do not impose strong security requirements in case of aborts. One...

    Provided By Darmstadt University of Technology

  • White Papers // Dec 2008

    Security of Sanitizable Signatures Revisited

    Sanitizable signature schemes, as defined by the researcher, allow a signer to partly delegate signing rights to an-other party, called the sanitizer. That is, the sanitizer is able to modify a predetermined part of the original message such that the integrity and authenticity of the unchanged part is still verifiable....

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2013

    Reset Indifferentiability and its Consequences

    The authors complement these latter works in several ways. First, they show that any simulator satisfying the reset in-differentiability notion must be stateless and pseudo deterministic. Using this characterization they show that, with respect to reset in-differentiability, two ideal models are either equivalent or incomparable, that is, a model cannot...

    Provided By Darmstadt University of Technology

  • White Papers // Feb 2010

    On the Impossibility of Three-Move Blind Signature Schemes

    The authors investigate the possibility to prove security of the well-known blind signature schemes by the researchers in the standard model, i.e., without random oracles. They subsume these schemes under a more general class of blind signature schemes and show that finding security proofs for these schemes via black-box reductions...

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2010

    Random Oracles With(out) Programmability

    In this paper, the authors investigate the Random Oracle Model (ROM) feature known as programmability, which allows security reductions in the ROM to dynamically choose the range points of an ideal hash function. This property is interesting for at least two reasons: because of its seeming artificiality (no standard model...

    Provided By Darmstadt University of Technology

  • White Papers // Sep 2010

    Security and Privacy in Online Social Networks

    In this paper, the authors deal with security in Online Social Networks (OSN). It introduces Online Social Networks as the digital representations of relationships, which their users entertain in the physical world. Social Network Providers (SNP), commonly commercial entities that offer Social Networking Services (SNS), the access to the OSN,...

    Provided By Darmstadt University of Technology