Connecting to the remote input gives RSA values:

```
nc jh2i.com 50013
Generating public and private key...
Public Key in the format (e,n) is: (65537,31378393096163)
The Encrypted PIN is 26169559602561
What is the PIN?
```

FactorDB fully factors public key (n, 31378393096163). That gives p and q. Then just do standard RSA with those values and send back pin (3093)

[Full writeup](https://bigpick.github.io/TodayILearned/articles/2020-06/nahamConCTF-writeups#twinning)