## Solution Steps* Identify that the type of cipher that requires a matrix is called a Hill cipher. This can be Googled: "type of cipher that uses a matrix"* Using [dCode](https://www.dcode.fr/hill-cipher), copy and paste the ciphertext into the text box along with the provided matrix values.* It is also possible to solve this [manually](https://youtu.be/JK3ur6W4rvw).* Flag: `jctf{hiTHEREwelcomeTOlinearALGEBRAZ}`
## Knowledge and/or Tools Needed* [MITRE ATT&CK® Technique T1140 - Deobfuscate/Decode Files or Information](https://attack.mitre.org/techniques/T1140/)* [Hill Cipher](https://en.wikipedia.org/wiki/Hill_cipher)* [dCode](https://www.dcode.fr/hill-cipher)