Deadline 12.10.2019 23:59

1. Generate random key K for aes128 and save it to K.bin. [1 point] 
2. Encrypt securely the message "This is my UCO_XXXXXX" stored in the file plaintext.txt using aes128 and key in K.bin [2]
3. Compute MAC of the message using sha256 with string "sharedsecret" used as shared secret. [2]
4. Decrypt ciphertext.txt to plaintext.txt and verify the MAC. [2]
5. Use shattered-1.pdf, shattered-2.pdf files and find other SHA1 collision (new files shattered-3.bin, shattered-4.bin with the same sha1 hash i.e. sha1(shattered-3.bin)=sha1(shattered-3.bin) != sha1(shattered-1.pdf) ). New files do not need to be openable pdf files. [3]
Hint: Look at the design of SHA1 (how new block is processed).

6. Describe shortly entire process, commands you used in Desc_XXXX.txt. 
The format of Desc_XXXX should be as follows:
openssl r...
openssl enc...
...

openssl sha1(shattered-3.bin)
openssl sha1(shattered-4.bin)

#comments  
1. Used standard ...
2. I used ... which is stored ...
3.
...
6. I used shattered-1.pdf,shattered-3.pdf and performed .... to get new shattered-3.bin, shattered-4.bin.

Archive all files and upload it as a single file XXXX.zip (XXXX stands for your UCO) to IS Assignement01 vault.