| karity-crackme-F |
password: KARITY{1nv3rt_th3_n0rm_fl0w!!}
custom neural network with 5 iterations of linear and relu layers with skip connections
state update: X_next = Z || Y[0..14]
flag is the mathematical hint: "invert the normal flow!!"
solved step-by-step backwards deterministically:
Y[0..14] is extracted directly from the second half of X_next
Y[15..29] is recovered by subtracting layer 2 ReLU outputs from Z
X is solved using 30x30 gaussian elimination modulo 256
solved by implementing a custom math solver in rust in under 25ms |
2026-07-07 18:17 |
| karity-crackme-D |
password (interactive): x6}$W~L6|?
password (non-interactive): *4{Z2j?ZZ
custom vm bytecode executes fnv-1a 64-bit hash on a 32-byte zero-padded buffer
target constant: 0x9E3779B97F4A7C15
modular inverse prime (mod 2^64): 0xCE965057AFF6957B
solved by implementing a custom meet-in-the-middle solver in rust |
2026-07-07 17:53 |