The first three write-ups are mine, the others are some interesting ones I've found.
I participated to the second edition of the bookCTF, there is two simple challenge with RSA
Two write-up that I've made on two CTF at the same time. The first challenge is about RSA and the second one DH
a good challenge that I'v done with a friend at the Midnight Sun CTF. We get a privet key with hidden part and from the clear part, we need to recover the entire key
an hard challenge that I tryied at the 2020 FCSC. This challenge is really hard and the code solution is in C and python
Same challenge from the same CTF but less hard and you only need python
All the write-up from the 2020 CryptoCTF by the Cryptohack team
All the write-up from the 2021 CryptoCTF by the Cryptohack team (i was into it ! but they were too fast for me xD )
you can find all the write-up about crypto of the 2021 FCSC ctf made by Enoent
Nice write-up about coppersmith