Converses For Secret Key Agreement and Secure Computing
ABSTRACT
We consider information theoretic secret key agreement and secure function computation by multiple partiesobserving correlated data, with access to an interactive publiccommunication channel. Our main result is an upper bound onthe secret key length, which is derived using a reduction of binaryhypothesis testing to multiparty secret key agreement. Buildingon this basic result, we derive new converses for multipartysecret key agreement. Furthermore, we derive converse results forthe oblivious transfer problem and the bit commitment problemby relating them to secret key agreement. Finally, we derive anecessary condition for the feasibility of secure computation bytrusted parties that seek to compute a function of their collectivedata, using an interactive public communication that by itselfdoes not give away the value of the function. In many cases,we strengthen and improve upon previously known conversebounds. Our results are single-shot and use only the given jointdistribution of the correlated observations. For the case when thecorrelated observations consist of independent and identicallydistributed (in time) sequences, we derive strong versions ofpreviously known converses.
SYSTEM ANALYSIS
EXISTING SYSTEM
Given two RVs X and Y , a central question of informationtheoretic secrecy. How many unbiased,independent bits can be extracted from that are unavailableto an observer of Y. When the underlying distribution is IID,the optimum rate of extracted bits can be expressed in termsof Shannon entropies.
However, forour single-shot setup, smooth min-entropy introduced is a more relevant measure of randomness. We use thedefinition of smooth min-entropy introduced for a review of other variations. We also review the leftover hash lemma, whichbrings out the central role of smooth min-entropy in theanswer to the question above. Also, as a “change of measurecompanion” for smooth min-entropy, we define smoothmax-divergence and note that it satisfies the data processinginequality.
EXISTING SYSTEM ALGORITHMS
In addition to the DH key agreement based on theDiscrete Logarithm Problem, there also exist ECCvariants, which require a smaller key size resulting
in less energy, memory, and bandwidth consumption.DH-based key agreement protocols are designedfor synchronous communications as opposed to theasynchronous Elliptic Curve Integrated EncryptionScheme (ECIES).
PROPOSED SYSTEM
Our approach brings out a structural connection betweenSK agreement and binary hypothesis testing4. This is in the spirit where a connection between channel codingand binary hypothesis testing was used to establish an upperbound on the rate of good channel codes. Also, our upper bound is reminiscent of the measureof entanglement for a quantum state proposed in namelythe minimum distance between the density matrix of the stateand that of a disentangled state.
This measure of entanglementwas shown to be an upper bound on the entanglement ofdistillation where the latter is the largest proportionof maximally entangled states that can be distilled using a purification process.
Using our basic result, we obtain new converses for SK agreement, and also, for secure two-party computation byreducing SK agreement to oblivious transfer and bit commitment.In many cases, we strengthen and improve upon previouslyknown results. Our main contributions are summarizedbelow.
PROPOSED SYSTEM ALGORITHMS
Selection Sort
It will use for find the Upper Bound of the value
MODULE DESCRIPTION
MODULE
Case Study and Data Collection
User
Key Generation
File Sharing
MODULE DESCRIPTION
Case Study and Data Collection
We consider a case study of a web-based collaborationapplication for evaluating performance. The applicationallows users to store, manage, and share documents anddrawings related to large construction projects. The servicecomposition required for this application includes: Firewall(x1), Intrusion Detection (x1), Load Balancer (x1), WebServer (x4), Application Server (x3), Database Server (x1),Database Reporting Server (x1), Email Server (x1), andServer Health Monitoring (x1). To meet these requirements,our objective is to find the best Cloud service composition
- USER
The problem of secure two-party computation was introduced by Yao. Two (mutually untrusting) parties seekto compute a function of their collective data, without sharinganything more about their data than what is given away by the
For two parties, the problem of SK agreement from correlatedobservations is well-studied. The problem was introduced by Maurer and Ahlswede and Csisz´ar, who consideredthe case where the parties observe IID sequences. However,in certain applications it is of interest to consider observationsarising from a single realization of correlated RVs. Forinstance, in applications such as biometric and hardware authentication(cf. [51], [20]), the correlated observations consistof different versions of the biometric and hardware signatures,respectively, recorded at the registration and the authenticationstages. To this end, Renner and Wolf [60] derived boundson the length of a SK that can be generated by two partiesobserving a single realization of correlated RVs, using onesidecommunication.
Upload File
The user can upload the file to DB. And the Admin can allow the data to store the DB.
Send Request
The user send request to others files downloading.
- Key Generation
The problem of SK agreement with multiple parties, forthe IID setup, was introduced in. In thiswork, we consider the SK agreement problem for multipleparties observing a single realization of correlated RVs. Ourconditional independence testing bound is a single-shot upperbound on the length of SKs that can be generated bymultiple parties observing correlated data, using interactivepublic communication5. Unlike the single-shot upper bound in, which is restricted to two parties with one-waycommunication, we allow arbitrary interactive communicationbetween multiple parties. Asymptotically our bound is tight– its application to the IID case recovers some previouslyknown (tight) bounds on the asymptotic SK rates. In fact, westrengthen the previously known asymptotic results since wedo not require the probability of error in SK agreement or thesecrecy index to be asymptotically. See Section IV for adetailed discussion.
Security Key
The Files Security Keyword generate at the time of file uploading.
Secret Key
The Users Secret Key Updated By Their Acctions.
- File Sharing
In multiparty SK agreement, a set of parties observingcorrelated random variables (RVs) seek to agree on sharedrandom bits that remain concealed from an eavesdropperwith access to a correlated side information. The partiesmay communicate with each other over a noiseless publicchannel, but the transmitted communication will be availableto the eavesdropper. The main tool for deriving our converseresults is a reduction argument that relates multiparty SKagreement to binary hypothesis testing3. For an illustrationof our main idea, consider the two party case when theeavesdropper observes only the communication between thelegitimate parties and does not observe any additional sideinformation. Clearly, if the observations of the legitimateparties are independent, a SK cannot be generated. We upperbound the length of SKs that can be generated in terms of “howfar” is the joint distribution of the observations of the partiesfrom a distribution that renders their observations independent.Specifically, for this special case, we show that the maximumlength S of a SK for a given secrecy index.
SYSTEM SPECIFICATION
Hardware Requirements:
•System: Pentium IV 2.4 GHz.
•Hard Disk : 40 GB.
•Floppy Drive: 1.44 Mb.
•Monitor : 14’ Colour Monitor.
•Mouse: Optical Mouse.
•Ram : 512 Mb.
Software Requirements:
•Operating system : Windows 7 Ultimate.
•Coding Language: ASP.Net with C#
•Front-End: Visual Studio 2010 Professional.
•Data Base: SQL Server 2008.