Official Broken Decryptor Discussion

Official discussion thread for Broken Decryptor. Please do not post any spoilers or big hints.

Very nice challenge. Took me a bit of time to realize that I was doing things right just was missing one extra step to recover everything.

Very good challenge.

Will the decrypt function never work?

@p00dl3 said:

Will the decrypt function never work?

My result: a really “broken decryptor”.

Fun challenge. Thx r4j! Forces you to understand MODE_CTR…(not a spoiler)

hi could someone give me a hint in DM?

Cant seem to break this, the randomness after each encryption makes it seem impossible to crack

@p00dl3 said:
Cant seem to break this, the randomness after each encryption makes it seem impossible to crack

Are you sure it is totally random?

Just solved the challenge, but it requires a long time and lots of requests to get flag. Is that normal, or that is intended?

I cannot yet discover how to get hid of the otp… Is it necessary to try to discover a prediction on the random bytes sequence?

@mysteriousP Read carefully the otp… generation and understand all steps of the generation. Fukurou and indirect maple3142 gives already very good hints.

Wohay! Finally i got it…
But, i wanted to discuss the method, because i think i made it in a naive way…
I’m thinking: if i could use some concurrency i should get better result?

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@Fukurou Thanks for helping me out in this challange