Tags: hill-cipher invaders mj0ln1r crypto
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# jack-and-jill
Ciphertext is given : `pgQVJFCohpccuyBSbwxcxpVZCAATRT`. A 2x2 matrix is given [[3,9],[4,7]].
By observing the description i found that this is a `hill cipher`. I quickly searched for the hill cipher decoder online. I used this site to decipher the text.
The deciphered text is **`hiTHEREwelcomeTOlinearALGEBRAZ`**
> `Flag : jctf{hiTHEREwelcomeTOlinearALGEBRAZ}`
## [Original Writeup](https://themj0ln1r.github.io/posts/jerseyctf23)