Ibaraki University

Displaying 1-11 of 11 results

  • White Papers // Nov 2013

    Kurosawa-Desmedt Key Encapsulation Mechanism, Revisited

    While the hybrid public key encryption scheme of kurosawa and desmedt (CRYPTO 2004) is provably secure against chosen cipher-text attacks (namely, IND-CCA-secure), its associated Key Encapsulation Mechanism (KEM) is not IND-CCA-secure. In this paper, the authors show a simple twist on the kurosawa-desmedt KEM turning it into a scheme with...

    Provided By Ibaraki University

  • White Papers // Aug 2012

    New Leakage Resilient CCA-Secure Public Key Encryption

    Building cryptographic schemes secure even if the secrets are partially leaked is a trend in cryptography, motivating partially from side channel attacks. In this paper, the authors are interested in Public Key Encryption (PKE) schemes with leakage resilience. This paper shows a generic method of constructing CCA- secure Public Key...

    Provided By Ibaraki University

  • White Papers // Apr 2012

    Relation Between Verifiable Random Functions and Convertible Undeniable Signatures, and New Constructions

    Verifiable Random Functions (VRF) and Selectively-Convertible Undeniable Signature (SCUS) schemes were proposed independently in the literature. In this paper, the authors observe that they are tightly related. This directly yields several deterministic SCUS schemes based on existing VRF constructions. In addition, they create a new probabilistic SCUS scheme, which is...

    Provided By Ibaraki University

  • White Papers // Mar 2012

    Maximum Leakage Resilient IBE and IPE

    In the model of identity-based encryption, first proposed by Shamir, one can use arbitrary strings as public keys. The research on IBE is an active and stimulating field of cryptography, and so far IBE schemes have been constructed under several assumptions: pairing-related assumptions, quadratic residue-related assumptions and lattice-related assumptions. Akavia...

    Provided By Ibaraki University

  • White Papers // Jan 2011

    A Graph-Based New Amortization Scheme for Multicast Streams Authentication

    The authors present a graph-based new amortization scheme for multicast streams authentication that achieves stronger resistance against packet loss and reduces the overhead in the same time. The hash chains of the existing amortization schemes have no systematic way to construct them, the construction had been determined by simulation. These...

    Provided By Ibaraki University

  • White Papers // Dec 2010

    Signing the First Packet in Amortization Scheme for Multicast Stream Authentication

    Signature amortization schemes have been introduced for authenticating multicast streams, in which, a single signature is amortized over several packets. The hash value of each packet is computed, some hash values are appended to other packets, forming what is known as hash chain. These schemes divide the stream into blocks,...

    Provided By Ibaraki University

  • White Papers // Aug 2010

    Round-Efficient Perfectly Secure Message Transmission Scheme Against General Adversary

    In the model of Perfectly Secure Message Transmission schemes (PSMTs), there are n channels between a sender and a receiver, and they share no key. An infinitely powerful adversary A can corrupt (observe and forge) the messages sent through some subset of n channels. For non-threshold adversaries called Q2, Kumar...

    Provided By Ibaraki University

  • White Papers // Jun 2010

    Provably Secure Convertible Undeniable Signatures With Unambiguity

    This paper shows some efficient and provably-secure convertible undeniable signature schemes (with both selective conversion and all conversion), in the standard model and discrete logarithm setting. They further satisfy unambiguity, which is traditionally required for anonymous signatures. Brie y, unambiguity means that it is hard to generate a (message, signature)...

    Provided By Ibaraki University

  • White Papers // Dec 2009

    Multiple Subcarrier Indoor Geolocation System in MIMO-OFDM WLAN APs Structure

    This report aims to utilize existing and future Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing Wireless Local Area Network (MIMO-OFDM WLAN) systems characteristics - such as multiple subcarriers, multiple antennas, and channel estimation characteristics - for indoor location estimation systems based on the Direction of Arrival (DOA) and Radio Signal Strength...

    Provided By Ibaraki University

  • White Papers // Dec 2008

    Truly Efficient 2-Round Perfectly Secure Message Transmission Scheme

    In the model of Perfectly Secure Message Transmission schemes (PSMTs), there are n channels between a sender and a receiver. An infinitely powerful adversary A may corrupt (Observe and forge) the messages sent through t out of n channels. The sender wishes to send a secret s to the receiver...

    Provided By Ibaraki University

  • White Papers // Sep 2006

    New Approach for Selectively Convertible Undeniable Signature Schemes

    In this paper, the authors propose a new approach for constructing selectively convertible undeniable signature schemes, and present two efficient schemes based on RSA. Their approach allows a more direct selective conversion than the previous schemes, and the security can be proved formally. Further, their disavowal protocols do not require...

    Provided By Ibaraki University

  • White Papers // Aug 2012

    New Leakage Resilient CCA-Secure Public Key Encryption

    Building cryptographic schemes secure even if the secrets are partially leaked is a trend in cryptography, motivating partially from side channel attacks. In this paper, the authors are interested in Public Key Encryption (PKE) schemes with leakage resilience. This paper shows a generic method of constructing CCA- secure Public Key...

    Provided By Ibaraki University

  • White Papers // Apr 2012

    Relation Between Verifiable Random Functions and Convertible Undeniable Signatures, and New Constructions

    Verifiable Random Functions (VRF) and Selectively-Convertible Undeniable Signature (SCUS) schemes were proposed independently in the literature. In this paper, the authors observe that they are tightly related. This directly yields several deterministic SCUS schemes based on existing VRF constructions. In addition, they create a new probabilistic SCUS scheme, which is...

    Provided By Ibaraki University

  • White Papers // Nov 2013

    Kurosawa-Desmedt Key Encapsulation Mechanism, Revisited

    While the hybrid public key encryption scheme of kurosawa and desmedt (CRYPTO 2004) is provably secure against chosen cipher-text attacks (namely, IND-CCA-secure), its associated Key Encapsulation Mechanism (KEM) is not IND-CCA-secure. In this paper, the authors show a simple twist on the kurosawa-desmedt KEM turning it into a scheme with...

    Provided By Ibaraki University

  • White Papers // Sep 2006

    New Approach for Selectively Convertible Undeniable Signature Schemes

    In this paper, the authors propose a new approach for constructing selectively convertible undeniable signature schemes, and present two efficient schemes based on RSA. Their approach allows a more direct selective conversion than the previous schemes, and the security can be proved formally. Further, their disavowal protocols do not require...

    Provided By Ibaraki University

  • White Papers // Dec 2009

    Multiple Subcarrier Indoor Geolocation System in MIMO-OFDM WLAN APs Structure

    This report aims to utilize existing and future Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing Wireless Local Area Network (MIMO-OFDM WLAN) systems characteristics - such as multiple subcarriers, multiple antennas, and channel estimation characteristics - for indoor location estimation systems based on the Direction of Arrival (DOA) and Radio Signal Strength...

    Provided By Ibaraki University

  • White Papers // Dec 2008

    Truly Efficient 2-Round Perfectly Secure Message Transmission Scheme

    In the model of Perfectly Secure Message Transmission schemes (PSMTs), there are n channels between a sender and a receiver. An infinitely powerful adversary A may corrupt (Observe and forge) the messages sent through t out of n channels. The sender wishes to send a secret s to the receiver...

    Provided By Ibaraki University

  • White Papers // Aug 2010

    Round-Efficient Perfectly Secure Message Transmission Scheme Against General Adversary

    In the model of Perfectly Secure Message Transmission schemes (PSMTs), there are n channels between a sender and a receiver, and they share no key. An infinitely powerful adversary A can corrupt (observe and forge) the messages sent through some subset of n channels. For non-threshold adversaries called Q2, Kumar...

    Provided By Ibaraki University

  • White Papers // Jun 2010

    Provably Secure Convertible Undeniable Signatures With Unambiguity

    This paper shows some efficient and provably-secure convertible undeniable signature schemes (with both selective conversion and all conversion), in the standard model and discrete logarithm setting. They further satisfy unambiguity, which is traditionally required for anonymous signatures. Brie y, unambiguity means that it is hard to generate a (message, signature)...

    Provided By Ibaraki University

  • White Papers // Dec 2010

    Signing the First Packet in Amortization Scheme for Multicast Stream Authentication

    Signature amortization schemes have been introduced for authenticating multicast streams, in which, a single signature is amortized over several packets. The hash value of each packet is computed, some hash values are appended to other packets, forming what is known as hash chain. These schemes divide the stream into blocks,...

    Provided By Ibaraki University

  • White Papers // Jan 2011

    A Graph-Based New Amortization Scheme for Multicast Streams Authentication

    The authors present a graph-based new amortization scheme for multicast streams authentication that achieves stronger resistance against packet loss and reduces the overhead in the same time. The hash chains of the existing amortization schemes have no systematic way to construct them, the construction had been determined by simulation. These...

    Provided By Ibaraki University

  • White Papers // Mar 2012

    Maximum Leakage Resilient IBE and IPE

    In the model of identity-based encryption, first proposed by Shamir, one can use arbitrary strings as public keys. The research on IBE is an active and stimulating field of cryptography, and so far IBE schemes have been constructed under several assumptions: pairing-related assumptions, quadratic residue-related assumptions and lattice-related assumptions. Akavia...

    Provided By Ibaraki University