TLDR

- Figure out this is LCS35 Time Capsule Crypto-Puzzle.

- Try to factor n. Succeed.

- Apply Euler’s theorem and solve the puzzle to get the flag.

Read complete writeup: [https://sectt.github.io/writeups/CryptoCTF19/crypto_timecapsule/README](https://sectt.github.io/writeups/CryptoCTF19/crypto_timecapsule/README)

Original writeup (https://sectt.github.io/writeups/CryptoCTF19/crypto_timecapsule/README).