The Experts below are selected from a list of 9507 Experts worldwide ranked by ideXlab platform

Palash Sarkar - One of the best experts on this subject based on the ideXlab platform.

  • tweakable enciphering schemes using only the Encryption Function of a block cipher
    Information Processing Letters, 2011
    Co-Authors: Palash Sarkar
    Abstract:

    A new construction of block cipher based tweakable enciphering schemes (TES) is described. The major improvement over existing TESs is that the construction uses only the Encryption Function of the underlying block cipher. Consequently, this leads to substantial savings in the size of hardware implementation of TES applications such as disk Encryption. This improvement is achieved without loss in efficiency of Encryption and decryption compared to previously known schemes. We further show that the same idea can also be used with a stream cipher which supports an initialization vector (IV) leading to the first example of a TES from such a primitive.

  • Tweakable Enciphering Schemes Using Only the Encryption Function of a Block Cipher.
    IACR Cryptology ePrint Archive, 2009
    Co-Authors: Palash Sarkar
    Abstract:

    A new construction of block cipher based tweakable enciphering schemes (TES) is described. The major improvement over existing TES is that the construction uses only the Encryption Function of the underlying block cipher. Consequently, this leads to substantial savings in the size of hardware implementation of TES applications such as disk Encryption. This improvement is achieved without loss in efficiency of Encryption and decryption compared to the best previously known schemes.

Willy Susilo - One of the best experts on this subject based on the ideXlab platform.

  • self generated certificate public key cryptography and certificateless signature Encryption scheme in the standard model extended abstract
    Computer and Communications Security, 2007
    Co-Authors: Joseph K Liu, Willy Susilo
    Abstract:

    Certificateless Public Key Cryptography (CL-PKC) enjoys a number of features of Identity-Based Cryptography (IBC) while without having the problem of key escrow. However, it does suffer from an attack where the adversary, Carol, replaces Alice's public key by someone's public key so that Bob, who wants to send an encrypted message to Alice, uses Alice's identity and other's public key as the inputs to the Encryption Function. As a result, Alice cannot decrypt the message while Bob is unaware of this. We call it Denial-of-Decryption (DoD) Attack as its nature is similar to the well known Denial-of-Service (DoS) Attack. Based on CL-PKC, we propose a new paradigm called Self-Generated-Certificate Public Key Cryptography (SGC-PKC) that captures the DoD Attack. We also provide a generic construction of a self-generated-certificate public key Encryption scheme in the standard model. Our generic construction uses certificateless signature and certificateless Encryption as the building block. In addition, we further propose a certificateless signature and a certificateless Encryption scheme with concrete implementation that are all provably secure in the standard model, which are the first in the literature regardless of the generic constructions by Yum and Lee which may contain security weaknesses as pointed out by others. We believe these concrete implementations are of independent interest.

  • self generated certificate public key cryptography and certificateless signature Encryption scheme in the standard model
    IACR Cryptology ePrint Archive, 2006
    Co-Authors: Joseph K Liu, Willy Susilo
    Abstract:

    Certificateless Public Key Cryptography (CL-PKC) enjoys a number of features of Identity-Based Cryptography (IBC) while without having the problem of key escrow. However, it does suffer to an attack where the adversary, Carol, replaces Alice’s public key by someone’s public key so that Bob, who wants to send an encrypted message to Alice, uses Alice’s identity and other’s public key as the inputs to the Encryption Function. As a result, Alice cannot decrypt the message while Bob is unaware of this. We call it Denial-of-Decryption (DoD) Attack as its nature is similar to the well known Denial-of-Service (DoS) Attack. Based on CL-PKC, we propose a new paradigm called Self-Generated-Certificate Public Key Cryptography (SGC-PKC) that captures the DoD Attack. We also provide a generic construction of a self-generated-certificate public key Encryption scheme in the standard model. Our generic construction uses certificateless signature and certificateless Encryption as the building block. In addition, we further propose a certificateless signature and a certificateless Encryption scheme with concrete implementation that are all provably secure in the standard model, which are the first in the literature regardless of the generic constructions by Yum and Lee which may contain security weaknesses as pointed out by others. We believe these concrete implementations are of independent interest.

Yang Yang - One of the best experts on this subject based on the ideXlab platform.

  • conjunctive keyword search with designated tester and timing enabled proxy re Encryption Function for e health clouds
    IEEE Transactions on Information Forensics and Security, 2016
    Co-Authors: Yang Yang
    Abstract:

    An electronic health (e-health) record system is a novel application that will bring great convenience in healthcare. The privacy and security of the sensitive personal information are the major concerns of the users, which could hinder further development and widely adoption of the systems. The searchable Encryption (SE) scheme is a technology to incorporate security protection and favorable operability Functions together, which can play an important role in the e-health record system. In this paper, we introduce a novel cryptographic primitive named as conjunctive keyword search with designated tester and timing enabled proxy reEncryption Function (Re-dtPECK), which is a kind of a time-dependent SE scheme. It could enable patients to delegate partial access rights to others to operate search Functions over their records in a limited time period. The length of the time period for the delegatee to search and decrypt the delegator’s encrypted documents can be controlled. Moreover, the delegatee could be automatically deprived of the access and search authority after a specified period of effective time. It can also support the conjunctive keywords search and resist the keyword guessing attacks. By the solution, only the designated tester is able to test the existence of certain keywords. We formulate a system model and a security model for the proposed Re-dtPECK scheme to show that it is an efficient scheme proved secure in the standard model. The comparison and extensive simulations demonstrate that it has a low computation and storage overhead.

Isamu Teranishi - One of the best experts on this subject based on the ideXlab platform.

  • relationship between standard model plaintext awareness and message hiding
    IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, 2008
    Co-Authors: Isamu Teranishi, Wakaha Ogata
    Abstract:

    Recently, Bellare and Palacio defined the plaintext awareness (PA-ness) in the standard model. In this paper, we study the relationship between the standard model PA-ness and the property about message hiding, that is, IND-CPA. Although these two notions seem to be independent at first glance, we show that PA-ness in the standard model implies the IND-CPA security if the Encryption Function is oneway. By using this result, we also showed that “PA + Oneway → IND-CCA2.” We also show that the computational PA-ness notion is strictly stronger than the statistical one.

  • relationship between standard model plaintext awareness and message hiding
    Lecture Notes in Computer Science, 2006
    Co-Authors: Isamu Teranishi, Wakaha Ogata
    Abstract:

    Recently, Bellare and Palacio succeeded in defining the plaintext awareness, which is also called PA2, in the standard model. They propose three valiants of the standard model PA2 named perfect, statistical, and computational PA2. In this paper, we study the relationship between the standard model PA2 and the property about message hiding, that is, IND-CPA. Although it seems that these two are independent notions at first glance, we show that all of the perfect, statistical, and computational PA2 in the standard model imply the IND-CPA security if the Encryption Function is oneway. By using this result, we also showed that PA2 + Oneway => IND-CCA2. This result shows the all-or-nothing aspect of the PA2. That is, a standard model PA2 secure public-key Encryption scheme either satisfies the strongest message hiding property. IND-CCA2, or does not satisfy even the weakest message hiding property, onewayness. We also showed that the computational PA2 notion is strictly stronger than the statistical one.

Pil Joong Lee - One of the best experts on this subject based on the ideXlab platform.