Hard Live

RSA Beginner

90 points

1101 Solves

Cryptography

Hard

intelagent moderator badge ctflearn++ badge

Community Rating: 4.51 / 5

I found this scribbled on a piece of paper. Can you make sense of it? https://mega.nz/#!zD4wDYiC!iLB3pMJElgWZy6Bv97FF8SJz1KEk9lWsgBSw62mtxQg

First 10 Solvers

Rank Username
1 voidmercy
2 limyunkai19
3 nandayo
4 katkatz
5 alexkato29
Rank Username
6 lzutao
7 niclev20
8 ross3102
9 joshualaurencio
10 android

  • superdedekind

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  • Peder ctflearn++ badge

    Woah finally solved, a bit hard

  • Major

    Thanks good challenge, found it a bit hard.

  • gosobog

    some help dont know from were to start

      • Ellexorcista

        Try using a factor database to factor you key n into p and q. Once you have that you should be able to calculate the rest. Good luck

          • CapitalZer0

            https://github.com/Ganapati/RsaCtfTool is a useful tool, although it does not have windows support

  • Bouke285

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  • MrHappy

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    • Bouke285

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      • MrHappy

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  • aikimonkey

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  • Enderaoe

    This is a good one, you almost got me when I stuck in the factor database step.

  • camus_

    was great learning exprience

  • yupwn

    good for beginner to understand basic asymmetric cryptography

  • H4cked

    Why isn't this the flag?

    P = 590872612825179551336102196593 Q = 416064700201658306196320137931 D = E^-1 mod ((P-1)(Q-1)) = 163894157674985901835273156607712429668627194783678277289707 M = C^D mod N = 219878849218803628752496734037301843801487889344508611639028^163894157674985901835273156607712429668627194783678277289707 mod(245841236512478852752909734912575581815967630033049838269083) = 142327357830311032682897538242625561166817486779261

    • one1

      You have to convert this value into ASCII text

  • elliot_pwn

    Maintain the decorum of Integer Factorization ;)