代做data编程、Python程序设计代写

日期：2025-07-16 06:51

Cryptography

SLP at NUAA in July 2025

Hands-On Individual Assignment

General Instruction

1. This is an individual assignment.

3. The Full Name and Student ID Number must be

stated in the email subject and the files specified below

attached as a single zip file.

4. You are allowed to submit only once, so triple check that

you have completed all tasks and attached all required files.

Tools

There are two options of commonly available libraries to use

1. OpenSSL

2. Python CryptoLibrary

Students are, of course, free to write and use their own

implementation of the relevant cryptographic modules, if they

so desire.

Care must be exercised to ensure that the submission package

can be evaluated on its own, without the submitter being

present to explain or argue a case.

Step-by-Step Procedures

1. Get a file of size between 1 to 10 MB and name this file

plaintext file.

• It is your responsibility to ensure that the chosen tool can

handle the file type of plaintext file.

• The file extension depends on the file type.

2. Hash plaintext file using SHA-512.

Output the digest to a file named digest file.hex in

hexadecimal format.

Procedures (continued)

3. Generate an RSA-4096 key pair.

• Output and save the public key in PEM format as

RSA public key.pem.

• Output and save the private key in PEM format as

RSA private key.pem.

4. Sign plaintext file using the RSA private key above and

output as signed file.

Verify the signature by using the RSA public key.

Procedures (continued)

5. Generate an AES-256 key and output the binary string as

AES key.txt.

6. Encrypt the AES key by using the RSA public key and

output as encrypted AES key.txt.

7. Decrypt encrypted AES key.txt by using the RSA private

key and output as a binary string into a file named

decrypted AES key.txt.

Ensure that the content is identical with AES key.txt.

Procedures (continued)

8. Encrypt plaintext file by using the AES key in any

mode of operation of your choice, e.g., Galois Counter

Mode (GCM).

9. Output the encrypted file as ciphertext file and specify

the chosen mode of operation.

• To decrypt the encrypted file, some modes of operation

require additional data (AAD) and initialization vector

(IV).

• You must know how to store, find, and use them.

• Some commands or routines allow for automatic handling of

AAD or IV.

Procedures (continued)

10. Decrypt ciphertext file and save the output as

decrypted file.

11. Output the SHA-512 digest of decrypted file, in

hexadecimal, as digest decrypted file.hex.

The grader will check for correctness by comparing the two

digest files.

Submission Package

Submit the following files in a single zip file containing

plaintext file digest file.hex

RSA public key.pem RSA private key.pem

signed file AES key.txt

encrypted AES key.txt decrypted AES key.txt

ciphertext file decrypted file

digest decrypted file.hex

• Students may add a list of commands or append the source

codes that they use as additional information in the

submission package.

• Doing so is not required but may make it easier for the

grader to assess the submission.

Have Fun

• You are free to discuss with other students.

• Your submission, however, is individual.

• There should not be identical plaintext file.

• If there are n students with very similar submission

packages with the lowest mark being X points, then the

individual mark will be X divided by n.

Enjoy!!