| Year | CTF | Problem | Genre | Keywords |
|---|---|---|---|---|
| 2021 | WaniCTF | Simple conversion | Crypto | long_to_bytes |
| 2021 | WaniCTF | Easy | Crypto | 線形変換の逆変換 |
| 2021 | SECCON4b | simple RSA | Crypto | RSA:Low Public Exponent Attack |
| 2021 | SECCON4b | Logical SEESAW | Crypto | AND |
| 2021 | setodaNoteCTF | base64 | Crypto | base64 |
| 2021 | setodaNoteCTF | ROT13 | Crypto | caesar |
| 2021 | setodaNoteCTF | pui_pui | Crypto | bytes -> hex |
| 2021 | setodaNoteCTF | tkys_secret_service | Crypto | 単一換字暗号 |
| 2021 | setodaNoteCTF | lets_bake | Crypto | cyber shef |
| 2021 | setodaNoteCTF | vul_rsa01 | Crypto | RSA:法nが素因数分解可能 |
| 2021 | setodaNoteCTF | vul_rsa02 | Crypto | RSA:Wiener's Attack |
| 2021 | setodaNoteCTF | WEARECIA | Crypto | Vignere暗号, Kryptos |
| 2021 | corCTF | fibinary | Crypto | 線形変換の逆変換 |
| 2021 | corCTF | 4096 | Crypto | RSA:Many Primes, 法nが素因数分解可能 |
| 2021 | CakeCTF | discrete log | Crypto | Eulerの定理 |
| 2021 | CakeCTF | Together as one | Crypto | 二項定理,Fermatの小定理,GCD |
| 2021 | NITIC CTF | |||
| 2021 | ACSC | RSA stream | Crypto | RSA:Common Modulus Attack |