Results 1  10
of
25
can mobile agents do secure electronic transactions on untrusted hosts? A survey of the security issues and the current solutions
 ACM Trans. Internet Technol
, 2003
"... This article investigates if and how mobile agents can execute secure electronic transactions on untrusted hosts. An overview of the security issues of mobile agents is first given. The problem of untrusted (i.e., potentially malicious) hosts is one of these issues, and appears to be the most diffic ..."
Abstract

Cited by 40 (0 self)
 Add to MetaCart
This article investigates if and how mobile agents can execute secure electronic transactions on untrusted hosts. An overview of the security issues of mobile agents is first given. The problem of untrusted (i.e., potentially malicious) hosts is one of these issues, and appears to be the most difficult to solve. The current approaches to counter this problem are evaluated, and their relevance for secure electronic transactions is discussed. In particular, a stateoftheart survey of mobile agentbased secure electronic transactions is presented. Categories and Subject Descriptors: A.1 [Introductory and Survey]; E.3 [Data Encryption];
On Securely Scheduling A Meeting
 In Proc. of IFIP SEC
, 2001
"... When people want to schedule a meeting, their agendas must be compared to find a time suitable for all participants. At the same time, people want to keep their agendas private. This paper presents several approaches which intend to solve this contradiction. A custommade protocol for secure meeting ..."
Abstract

Cited by 16 (0 self)
 Add to MetaCart
(Show Context)
When people want to schedule a meeting, their agendas must be compared to find a time suitable for all participants. At the same time, people want to keep their agendas private. This paper presents several approaches which intend to solve this contradiction. A custommade protocol for secure meeting scheduling and a protocol based on secure distributed computing are discussed. The security properties and complexity of these protocols are compared. A tradeoff between trust and bandwidth requirements is shown to be possible by implementing the protocols using mobile agents. Keywords: mobile agents, secure distributed computation, meeting scheduling 1.
Fair TwoParty Computations via Bitcoin Deposits ⋆
"... Abstract. We show how the Bitcoin currency system (with a small modification) can be used to obtain fairness in any twoparty secure computation protocol in the following sense: if one party aborts the protocol after learning the output then the other party gets a financial compensation (in bitcoins ..."
Abstract

Cited by 12 (3 self)
 Add to MetaCart
(Show Context)
Abstract. We show how the Bitcoin currency system (with a small modification) can be used to obtain fairness in any twoparty secure computation protocol in the following sense: if one party aborts the protocol after learning the output then the other party gets a financial compensation (in bitcoins). One possible application of such protocols is the fair contract signing: each party is forced to complete the protocol, or to pay to the other one a fine. We also show how to link the output of this protocol to the Bitcoin currency. More precisely: we show a method to design secure twoparty protocols for functionalities that result in a “forced ” financial transfer from one party to the other. Our protocols build upon the ideas of our recent paper “Secure Multiparty Computations on Bitcoin ” (Cryptology ePrint Archive, Report 2013/784). Compared to that paper, our results are more general, since our protocols allow to compute any function, while in the previous paper we concentrated only on some specific tasks (commitment schemes and lotteries). On the other hand, as opposed to “Secure Multiparty Computations on Bitcoin”, to obtain security we need to modify the Bitcoin specification so that the transactions are “nonmalleable ” (we discuss this concept in more detail in the paper). 1
Applying General Access Structure to Metering Schemes
, 2002
"... In order to decide on advertisement fees for web servers, Naor and Pinkas [15] introduced metering schemes secure against coalition of corrupt servers and clients. In their schemes any server is able to construct a proof to be sent to an audit agency if and only if it has been visited by at least a ..."
Abstract

Cited by 8 (3 self)
 Add to MetaCart
(Show Context)
In order to decide on advertisement fees for web servers, Naor and Pinkas [15] introduced metering schemes secure against coalition of corrupt servers and clients. In their schemes any server is able to construct a proof to be sent to an audit agency if and only if it has been visited by at least a certain number of clients. After that in series of papers Masucci et. al. [13, 13, 14] generalized the idea of Naor and Pinkas proposing first metering scheme with pricing and dynamic multithreshold metering schemes and later applying general access structures and a linear algebraic approach to metering schemes.
On Distributed Key Distribution Centers and Unconditionally Secure Proactive Verifiable Secret Sharing Schemes based
 on General Access Structure, INDOCRYPT 2002, LNCS 2551
, 2002
"... S. Fehr [14] pointed out that denoting the complement ΓA = ∆c A [20, 13] as honest (or good) players structure appears to be a misleading term. Actually its dual access structure Γ ⊥ A should be called the honest (or good) players structure, since for any set G of good players the complement Gc is t ..."
Abstract

Cited by 4 (3 self)
 Add to MetaCart
(Show Context)
S. Fehr [14] pointed out that denoting the complement ΓA = ∆c A [20, 13] as honest (or good) players structure appears to be a misleading term. Actually its dual access structure Γ ⊥ A should be called the honest (or good) players structure, since for any set G of good players the complement Gc is the set of corrupted players from ∆A. This reflects in some changes of the notations in Theorem 2 and Theorem 4 from [20] as well as in changes of the notations for good players structure in some protocols. Abstract. A Key Distribution Center of a network is a server enabling private communications within groups of users. A Distributed Key Distribution Center is a set of servers that jointly realizes a Key Distribution Center. In this paper we build a robust Distributed Key Distribution Center Scheme secure against active and mobile adversary. We consider a general access structure for the set of servers and for the adversary access structure. We also revise the unconditionally secure Verifiable Secret Sharing Schemes from [11, 10, 20, 23] proposing a modified version which is proactively secure. 1
MultiParty Computation from any Linear Secret Sharing Scheme Secure against Adaptive Adversary: The ZeroError Case
 ACNS’2003, LNCS
"... We use a general treatment of both informationtheoretic and cryptographic settings for MultiParty Computation (MPC), based on the underlying linear secret sharing scheme. Our goal is to study the Monotone Span Program (MSP), which is the result of local multiplication of shares distributed by two ..."
Abstract

Cited by 3 (3 self)
 Add to MetaCart
(Show Context)
We use a general treatment of both informationtheoretic and cryptographic settings for MultiParty Computation (MPC), based on the underlying linear secret sharing scheme. Our goal is to study the Monotone Span Program (MSP), which is the result of local multiplication of shares distributed by two given MSPs as well as the access structure that this resulting MSP computes. First, we expand the construction proposed by Cramer et al. multiplying two different general access structures and we prove some properties of the resulting MSP M. Next we expand the definition of multiplicative MSPs and we prove that when one uses dual MSPs only all players together can compute the product, i.e., the construction proposed by Cramer et al. gives only multiplicative MPC. Third, we propose a solution for the strongly multiplicative MPC (in presence of adversary). The knowledge of the resulting MSP and the access structure it computes allows us to build an analog of the algebraic simplification protocol of Gennaro et al. We show how to achieve in the computational model MPC secure against adaptive adversary in the zeroerror case, through the application of homomorphic commitments. There is an open problem how efficiently we can determine Γ the access structure of the resulting MSP M. This open problem reflects negatively on the efficiency of the proposed solution.
On Unconditionally Secure Distributed Oblivious Transfer
 PROGRESS IN CRYPTOLOGY: PROCEEDINGS OF INDOCRYPT 2002, LNCS, SPRINGERVERLAG
, 2002
"... This work is about distributed protocols for oblivious transfer, proposed by Naor and Pinkas, and recently generalized by Blundo et. al. In this settings a Sender has n secrets and a Receiver is interested in one of them. The Sender distributes the information about the secrets to m servers, and ..."
Abstract

Cited by 3 (0 self)
 Add to MetaCart
(Show Context)
This work is about distributed protocols for oblivious transfer, proposed by Naor and Pinkas, and recently generalized by Blundo et. al. In this settings a Sender has n secrets and a Receiver is interested in one of them. The Sender distributes the information about the secrets to m servers, and a Receiver must contact a threshold of the servers in order to compute the secret. These distributed oblivious transfer protocols provide information theoretic security. We present impossibility result and lower bound for existence of oneround threshold distributed oblivious transfer protocols, generalizing the results of Blundo et. al. A threshold based construction implementing 1outofn distributed oblivious transfer achieving the proved lower bound for existence is proposed. A
Secure Meeting Scheduling with Agenta
 Proceedings of IFIP Communications and Multimedia Security
, 2001
"... When people want to schedule a meeting, the agendas of the participants must be compared to nd a time suitable for all of them. However, at the same time participants want to keep their agendas private. This paper presents a negotiation protocol which tries to solve this contradiction. The protocol ..."
Abstract

Cited by 2 (1 self)
 Add to MetaCart
(Show Context)
When people want to schedule a meeting, the agendas of the participants must be compared to nd a time suitable for all of them. However, at the same time participants want to keep their agendas private. This paper presents a negotiation protocol which tries to solve this contradiction. The protocol is implemented in the agenTa system using mobile software agents, hereby alleviating communication overhead and allowing disconnected operation. Keywords: mobile agents, secure distributed computation, meeting scheduling 1.
Linear Secret Sharing from AlgebraicGeometric Codes
, 2005
"... It is wellknown that the linear secretsharing scheme (LSSS) can be constructed from linear errorcorrecting codes (Brickell [1], R.J. McEliece and D.V.Sarwate [2],Cramer, el.,[3]). The theory of linear codes from algebraicgeometric curves (algebraicgeometric (AG) codes or geometric Goppa code) h ..."
Abstract

Cited by 2 (2 self)
 Add to MetaCart
(Show Context)
It is wellknown that the linear secretsharing scheme (LSSS) can be constructed from linear errorcorrecting codes (Brickell [1], R.J. McEliece and D.V.Sarwate [2],Cramer, el.,[3]). The theory of linear codes from algebraicgeometric curves (algebraicgeometric (AG) codes or geometric Goppa code) has been welldeveloped since the work of V.Goppa and Tsfasman, Vladut, and Zink ( see [17], [18] and [19]). In this paper the linear secretsharing scheme from algebraicgeometric codes, which are nonthreshold schemes for curves of genus greater than 0, are presented. We analysis the minimal access structure, dmin and dcheat([8]), (strongly) multiplicativity and the applications in verifiable secretsharing (VSS) scheme and secure multiparty computation (MPC) of this construction([3] and [1011]). Our construction also offers many examples of the selfdually GF(q)representable matroids and many examples of new ideal linear secretsharing schemes addressing to the problem of the characterization of the access structures for ideal secretsharing schemes([3] and [9]). The access structures of the linear secretsharing schemes from the codes on elliptic curves are given explicitly. From the work in this paper we can see that the algebraicgeometric structure of the underlying algebraic curves is an important resource for secretsharing, matroid theory, verifiable secretsharing and secure multiparty
On the TradeOff Between Communication and Trust in Secure Computations
"... In this paper, we show that mobile code technology may prove to be a useful tool in advanced cryptographic protocols for secure distributed computing. ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
In this paper, we show that mobile code technology may prove to be a useful tool in advanced cryptographic protocols for secure distributed computing.