- use [https://github.com/Ganapati/RsaCtfTool](https://github.com/Ganapati/RsaCtfTool)
after installing the tool run command:
`python3 ~/RsaCtfTool/RsaCtfTool.py --publickey ./key.pub --uncipherfile mystery.txt`
in challenge directory and it'll spit the flag
### flag
`kqctf{y0uv3_6r4du473d_fr0m_r54_m1ddl3_5ch00l_abe7e79e244a9686efc0}`