Show Bid Request
DES ENCRYPTION IN MATLAB
Bid Request Id: 62497
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Posted by: |
bbrother4 (0 ratings)
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Non-action Ratio: |
Very Good - 0.00%
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Buyer Security Verifications: |
Good
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Approved on: |
May 11, 2003
9:30:01 AM EDT
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Bidding Closes: |
May 16, 2003
4:00:26 PM EDT
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Viewed (by coders): |
115 times
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Deadline: |
5/21/2003
TIME EXPIRED
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Description:
An implementation of the DES (data encryption standard) encryption mechanism must be built and then used to encrypt the plaintext strings given below (with defined keys).
1)work on the key generation aspects of the work
2work on the s-box generation
3work on the Permutation
4)And to works on the “ framework” for the algorithm operation; eg inputting key, plaintext etc.
OUTPUTS
Student report must include detailed design and software for the DES implementation. It must also include the ciphertext resulting from the following encryption operations:
PLAINTEXT KEY
1.ABCDEFABCDEFABCD 0123456789ABCDEF
2.ABCDEFABCDEFABC5 0123456789ABCDEF
HINTS
Various operations, which are required in order to implement the DES algorithm are supported by MATLAB. Of particular use are:
1) A means of reordering the elements of a matrix
2) Assume that X is one dimensional array represented as a matrix. X(1) is the first element of the array and X (n) is the nth. The matrix is therefore: X(1), X(2), X(3),………………. X(n-1), X(n). If r(n) is recording matrix: r(1), r(2), r(3)…………r(n-1), r(n). Then y=X(r ) will reorder the elements in X according to the indexing values in r. EG: let X=6,7.8, let r= 2,1,3 then if y=X(r), y=7,6,8
3) Structures can be built to rotate the elements of a matrix to the left or to the right. Assume that X is matrix as above:
Let y=X with elements rotated one place to the right:
Y=[X(n),X(1:n-1)],
Similarly, with all elements rotated one place to the left
Y=[X(2: n), X(1)]
Deliverables:
1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done.
2)Complete documentation of the functionality of the programs.
3) Complete ownership and distribution copyrights to all work purchased.
Platform:
Windows 98/2000/XP/NT,
MATLAB 6
Must be 100% finished and received by buyer on:
May 21, 2003 EDT
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Bidding/Comments:
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| Name |
Bid Amount
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Date |
Coder Rating |
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This bid was accepted by the buyer!
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$110 (USD)
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May 14, 2003
10:14:59 AM EDT
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10
(Excellent)
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Hello!
I have high experience in MATLAB (used it in university and at my current work for modelling various processes) and have written DES implementation in other languages, so it's not difficult for me to write it in MATLAB, following recomendations about matrix operations given in your request. Also I can write a description of each function used in program, based on FIPS PUB 46-2 document(DES standard). What interface required for the program? Is it sufficient to have main function DESencrypt(plaintext,key), which takes two 16-digit hex strings, as in your example, and returns 16-digit hex string of chiphertext? Then to verify how it works, you will have to type DESencrypt('ABCDEFABCDEFABCD', '0123456789ABCDEF') and the result will be printed. Of course, there will be other sub-functions, called by this one. All work will take about 2 days, or I can do it in a day if you don't want a separate detailed description of program design. But if you need such description, please tell me how much detailed should it be. And is there any need of decryption function?
With best regards,
Alexander Zharov. |
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