We are given the following text:
n = 128393532851463575343089974408848099857979358442919384244000744053339479654557691794114605827105884545240515605112453686433508264824840575897640756564360373615937755743038201363814617682765101064651503434978938431452409293245855062934837618374997956788830791719002612108253528457601645424542240025303582528541
e = 65537
c = 93825584976187667358623690800406736193433562907249950376378278056949067505651948206582798483662803340120930066298960547657544217987827103350739742039606274017391266985269135268995550801742990600381727708443998391878164259416326775952210229572031793998878110937636005712923166229535455282012242471666332812788
´c´ is the encrypted message, ´n´ is the modulus and ´e´ is the public exponent. To decrypt the message we need to factorize ´n´ to get the private key ´d´.
Checking
That means we can calcualte the private key
We use the following python script to decrypt the message:
from Crypto.Util.number import inverse
n = 128393532851463575343089974408848099857979358442919384244000744053339479654557691794114605827105884545240515605112453686433508264824840575897640756564360373615937755743038201363814617682765101064651503434978938431452409293245855062934837618374997956788830791719002612108253528457601645424542240025303582528541
e = 65537
c = 93825584976187667358623690800406736193433562907249950376378278056949067505651948206582798483662803340120930066298960547657544217987827103350739742039606274017391266985269135268995550801742990600381727708443998391878164259416326775952210229572031793998878110937636005712923166229535455282012242471666332812788
d = inverse(e, n-1)
m = pow(c, d, n)
print(bytes.fromhex(hex(m)[2:]).decode())
python3 solve.py
byuctf{d1d_s0m3_rs4_stuff...m1ght_d3l3t3_l4t3r}