The path to uncovering the secret is tangled in numbers—only the sharpest minds will find clarity.
This challenge involves solving a simple modular arithmetic equation. The encryption formula is:
c = (m * a + b) % p
To retrieve m from c, rearrange the equation as:
m = (c - b) * (a^-1) % p
Where a^-1 is the modular multiplicative inverse of a modulo p.
Here’s the solution code:
enc = [678296017,867140740,2721963345,2868842574,615347776,1035002716,2847859827,1391709415,2784911586,636330523,909106234,2763928839,1223847439,699278764,1223847439,2742946092,825175246,3393411249,2889825321,3393411249,1370726668,594365029,]
flag = ''
p = 4066351909
for e in enc:
t = ((e + 127389238) * pow(2022684581, -1, p)) % p
flag += chr(t)
print(flag)uctf{Sh1ny_pAsArg4d43}
- Web
- Reverse
- PWN
- Misc
- Forensics
- Cryptography
- Blockchain
- Steganography
- AI
- Data Science
| Warm up | This Challenge | Evil |
|---|---|---|
| 25 | 200 | 500 |