# A3
**Deadline:** Tuesday, 02/20/24, 11:59 pm
*This assignment may be done as individuals or with one partner. If you choose to work with a partner, you should submit one solution.*
A3 and A4 are a two-part assignment. This first part (A3) is due
on February 20. The second part (A4) is due of February 27. I expect A4 to take
longer than A3, so you might want to get started on that one early.
Unfortunately, I'm not going to post A4 on the website, I'm only going to give
you an encrypted copy of A4. Your task for this week is to
decrypt next week's assignment.
The following information may be useful: I encrypted A4 with hybrid encryption
using RSA-2048 with OAEP using SHA-256 and AES-256 in GCM. The starter files
for A3, which include the RSA secret key (formatted in the PKCS8 standard), an
encrypted copy of the AES key (formatted as a binary file), and the
AES-encrypted A4 (formatted as a zip file), are available
here.
The randomly-generated IV used during AES encryption is
0x5A27710DB8004E0C4CF00573F5665290. If there are any other parameters you think
would be useful to know, definitely ask!
Hint: You could use any cryptographic library of your choice to implement the
decryption, but you might find it helpful in the future if you use the same
language as you plan to use for your project.
**What to submit:** For A3, you should submit 1) the source code for a program that reads in the starter files and writes a (decrypted) file `a4.zip`, 2) a copy of the
decrypted assignment handout `a4.pdf` (which you can find in the decrypted zip file), and 3) a feedback form specifying how long you
spent on A3 and any comments or feedback on this assignment.