# Dragon CTF 2021: CRC Recursive Challenge (Warmup)

@blackb6a played Dragon CTF 2021 last weekend and I spent most of the time solving the CRC duo. They are very fun but unfortunately that we were close enough while unable to get the second flag.

# Balsn CTF 2021: dlog

@blackb6a played Balsn CTF 2021 last weekend. There are three crypto challenges, and they are all pretty hard. In this blog post we will cover the dlog challenge, which is a timing attack on the CPython’s pow method. @grhkm2023 and I spent a lot of time working on this challenge. Although we did not solve it, we actually learned a lot from the challenge and lost a pile of hair (maybe it is just me).

# HKCERT CTF 2021 Postmortem (IV): The Remaining Ones

We will cover the remaining challenges I wrote in this part: Flag Checker™, The Wilderness and Potion of Ciphermath.

# HKCERT CTF 2021 Postmortem (III): The Reverse Challenges

As the third part of the series, three reversing challenges will be included: The Hardest Path, A Junior Mathematician and Let’s Chill.

# HKCERT CTF 2021 Postmortem (II): Harder Crypto Challenges

In this part, three harder crypto challenges will be covered: Tenet: The Plagarism, Sratslla SEA and Sign in Please, Again.