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AES 128 encryption and decryption in java

$30-250 USD

Closed
Posted over 9 years ago

$30-250 USD

Paid on delivery
write a program that uses AES-128 to decrypt a message. The program should be named "decrypt" and should accept 3-command line arguments as follows: decrypt cipher_file key_file target_file where 'cipher_file' is the name of a file that contains the encrypted text as a stream of bytes. 'key_file' is the 128-bit key for decryption stored as a stream of bytes, and 'target_file' is the name of the file where the outcome of the decryption should be stored. To test this program, here's an example of an encrypted message (link) and its 128-bit secret key (link) (right click and choose "Save As" to save the files on your PC). PART 2(a): you will try to use "brute force" to decrypt an encrypted message, where you only have the first 96-bits of the 128-bit secret key (last 4 bytes of the secret key are missing!) The program should be called findk, and invoked as follows: findk cipher_file key_file where 'cipher_file' is the file containing the encrypted message and 'key_file' is the file containing the first 96-bits of the key. The program should print out on standard output the missing 4 bytes of the key in hexadecimal, the decrypted message and the time it took to find the correct key. To test this part, here is the encrypted file (link), and the first 96-bits of the key (link) (right click and choose "Save As" to save the file on your PC). Hint: the original message starts with the word "Salam".. PART 2(b) this part is the same as Part 2(a) but a more challenging key. Hint: the original message starts with the word "Hello".. Here is the encrypted file (link) and the first 96-bits of the key (link). PART 2(c) (optional for extra credit if broken) this part is similar to Part 2(a) but only the first 64-bits are available. Hint: The message starts with "Salam Nawaf". If you are not able to decrypt the data in time, it is enough to mention the time you ran the program for. Here is the encrypted file (link) and the first 64-bits of the key (link).
Project ID: 6604321

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13 proposals
Remote project
Active 9 yrs ago

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13 freelancers are bidding on average $166 USD for this job
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Hello I am Java expert and interested in this project. Can you share actual document containing details of the project, since there are some parts in description which isn't clear. Please communicate to discuss further. Regards Anshu
$263 USD in 3 days
4.7 (292 reviews)
7.1
7.1
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I am an expert in delivering custom scripts and willing to discuss further about the project specifications.
$189 USD in 3 days
4.8 (68 reviews)
6.8
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I have 9+ years of exp in c c++ java j2ee hibernate spring webservices databases. Done multiple projects like this and almost proficient in design patterns..Checkout my completion rate and reviews.
$211 USD in 3 days
5.0 (43 reviews)
5.5
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I'm a 5-year java software developer. I worked with encryption/decryption/hashing in java before. Kindly PM me for further discussion.
$225 USD in 10 days
5.0 (7 reviews)
4.5
4.5
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Hi, I am an experience java developer and I am looking forward to work with you on your project. I have previously worked with Java security API. Please feel free to pm me to discuss your project. Regards, Avi
$205 USD in 5 days
5.0 (2 reviews)
1.7
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$150 USD in 7 days
5.0 (1 review)
0.5
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Hello Sir, We have gone through the details you have provided and we have already worked on a similar project before and can deliver as u have mentioned and would be pleased to work on this with you to deliver the results that you have expected and we have already worked on a similar project before and can deliver as u have mentioned We are sure you will not be disappointed if you give us this opportunity. Our team is experienced, creative & efficient enough to get your job done well. We have an impeccable record and all our clients enjoy working with us, we are sure that you will too, our prices are cheapest in market. can u provide your email or sky-pe etc for further discussion about the project I am ready to discuss with you with best Regards
$222 USD in 7 days
5.0 (2 reviews)
0.0
0.0
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Hello! Dear client manager I have a rich experience at AES algorithm and its implementation. I read your description carefully. If the ciphertext is one that is encrypted by ecb mode, I can do this easily. sincerly!
$111 USD in 3 days
0.0 (0 reviews)
0.0
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I am a professional of security in java so I can easily do what you need.. contact me to send you a demo of job then if you accepted,I ll send you all program..
$60 USD in 3 days
0.0 (0 reviews)
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I'm definitely a person what u looking for. I'e studied cryptography at Moscow Institute of Physics and Technology and i've accepted sertificate from Cryptography course on coursera by Stanford.
$144 USD in 2 days
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$111 USD in 3 days
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Hi! I am an Information Security researcher and have worked as a Senior Java Developer in the past. I can do this task easily for you. Looking forward for your response.
$155 USD in 3 days
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Hi I am umapathi i have experience of 3+ years in java web application development. I have hands on experience in security, using AES and sha encryption Even in worked in ssl configuration using ketool Thanks in advance
$155 USD in 3 days
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Hi, not sure If I am the best option for you, but please consider it carefully. I have started to work as the common Java Developer (for about 3years), then I continued with J2EE for 4 another years and then I was promoted to higher level and that's SW Analyst / Architect. Currently I don't have much possibilities for Java development (as due to other duties as an Architect), therefore I am applying for such jobs like yours, so to be still in touch with pure coding and re-using my experiences in various projects. Therefore I could be good option for you.
$177 USD in 7 days
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