Behold! We invented the brand-new, super-difficult, hyper-cryptic, and ultra-undecipherable cryptosystem for this SECCON CTF 2019!
And we have the name of it: たぬき (Tanuki) !
Samples
Ciphertext 1: たたせくたこたたたんた
Plaintext 1: せくこん
Ciphertext 2: たSたEたたたたたCCたたたたたOたNたたた
Plaintext 2: SECCON
Oh, it's too difficult for you to decrypt? So then... TRY HARDER!