Software Programmer Job Request

Project Description

Given an input text message m, code the following algorithm: STEP 1: Compute the hash value from the input message m. In this step, you may choose to use an existing hash algorithm or to design your own hash function. STEP 2: Encrypt the hash value computed from STEP 1 with the sender's private key. You may choose any asymmetrical encryption algorithm studied in the subject. STEP 3: Append the encrypted hash value to the original message m, and then encrypt the augmented message using a session key of your choice. This step is using symmetrical encryption. You should consider using CBC, CFB and OFB modes. In addition, your encryption (and the corresponding decryption algorithm) should contain multiple rounds. You must code this part entirely yourself (no libraries). STEP 4: Encrypt the session key with the receiver’s public key. This step is using asymmetrical encryption. STEP 5: Append the encrypted key to the output of STEP 4. This is your final cipher message ready to be sent to the receiver. (Not required to actually send it).

Decryption and message integrity verification: Design and code a corresponding algorithm which help you to:

1. Decode and obtain the original message m, and
2. Verifying the integrity of message m.

Note the following:

1. The software can be written in any computer language you like e.g. Java, Perl, C++, C, bash shell or even be web based (PHP). Preferably Python or C
2. A debug version provides details of what is happening when encryption or decryption is taking place should also be provided. This could be implemented as a simple switch when the software is called from the command line or by some other means such as a debug variable which is set to true or false for the debug and standard versions respectively. At the very least the debug version should signal each stage of the encryption process and the inputs and outputs of each stage. It should be possible to capture an output in a text file or pause between each stage to allow examination of each stage. Sample captures should be provided to be demonstrated in front of an audience
3. You should avoid using existing libraries as much as you can. Note that the symmetrical encryption part MUST be of your own coding.
4. Please ensure the following: i. Code more functionality, instead of using the library function. ii. Ability to obtain the input and outputs at any stage of the project. iii. Optionally code a scenario where STEP 3 and 4 are replaced by asymmetrical encryption directly, and compare its execution time with the original algorithm. iv. Give some comments on the choice of hash function used. v. Comments on each line of code so I may understand and review it when completed.