Hard Live

Christmas Tree Hash

100 points

56 Solves



Community Rating: 4.63 / 5


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As Christmas approaches, Adam decides that he wants to improve his network security. He is inspired by the nearly identical Christmas Trees in his office with the only difference being the number on the star on top, and writes a hash function to generate a key. His instructions are found here: https://mega.nz/#!vawiwIBL!MNh3kyh12f_V8xtpHVCiBz5svr7Npvdhu6uzUkS08Tg - The trees in Adam's office can be found here (your input): https://mega.nz/#!PGw2SCDZ!yzI2DCX0ut-TR5WBDX2x_aqtNQezg9WTGcxcmHlNJNs - What is the encryption key generated by Adam's Christmas Tree Hash function?

First 10 Solvers

Rank Username
1 kronos
2 kalilo
3 Yeraisci
4 bakudanichi
5 intelagent moderator badge ctflearn++ badge
Rank Username
6 tenchijin
7 Anony
8 freimer
9 nh4ntz
10 thebadgod


    • Gilad ctflearn++ badge


      Any hint about step 7 - how to convert -682335424444623097 to uehcysuxjh? I've already tried several conversions of -682335424444623097 to other values

      • Gilad ctflearn++ badge


        never mind - I've found how to convert

    • IT_Oracle


      That was a fun programming challenge! Also, that flag made me do a double take and then made me laugh pretty hard, lmao. Thanks for the challenge!

    • Raffy


      Step 6 (line 34 of text1.txt) is confusing, the value you should be subtracting is 365^5 + 52^10 + 7^20 + 457981573849226022 (notice the last plus sign instead of the minus). Otherwise, good job.

    • airr


      Could someone explain me step 6

      • emo94


        try this in python: k = pow(365, 5) + pow(52, 10) + pow(7, 20) + 457981573849226022 - int(result) k = -k

        • emo94


          k =-k is a second line

    • IronLarreh_

      Protected 0.0

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