Challenge list
Network SecurityLevel 3★★★☆☆Network Analysis - SSL Strip Clear-text Credentials
An SSL Strip attack downgraded HTTPS to HTTP, so the victim's credentials traveled in clear text and were captured.…
Network SecurityLevel 3★★★☆☆Network Analysis - Unmasking WebSocket Frames
capture.pcap records WebSocket traffic between a browser and a chat server. Every client-to-server frame is masked…
Network SecurityLevel 3★★★☆☆Network Analysis - Custom Protocol Decoding
Traffic from a system using a small custom binary protocol was captured. Download the packet capture (traffic.pcap),…
CryptographyLevel 3★★★☆☆Cryptanalysis - RSA Common Modulus Attack
Two systems reused the same RSA modulus n and only changed the public exponent. The ciphertexts c1 and c2 of the same…
CryptographyLevel 3★★★☆☆Cryptanalysis - Diffie-Hellman with a Small Prime
An old IoT device performed Diffie-Hellman key exchange with a prime p of only 36 bits. handshake.txt contains p, g, A…
Network SecurityLevel 4★★★★☆Network Analysis - Rebuilding Chunked gzip HTTP from TCP
capture.pcap records two HTTP exchanges over one TCP connection. The server's segments are reordered and some are…
Network SecurityLevel 4★★★★☆Network Analysis - TCP Retransmission Covert Channel
capture.pcap contains TCP retransmissions with duplicate sequence numbers. Extract retransmissions whose payload…
CryptographyLevel 4★★★★☆Cryptanalysis - DSA Nonce Reuse Key Recovery
/challenge/signatures.json, created with fresh keys at every start, holds the DSA public parameters (p of 1024 bits, q…
CryptographyLevel 4★★★★☆Cryptanalysis - Wiener's Attack on RSA
An embedded-device team made the RSA private exponent d very small to speed up decryption. The public exponent e in…
CryptographyLevel 4★★★★☆Cryptanalysis - Recovering an LCG's Hidden Parameters
A service generated both session tokens and an encryption keystream from a linear congruential generator x_{k+1} =…
Network SecurityLevel 5★★★★★Network Analysis - IPv4 Overlapping Fragment Reassembly
The UDP datagram with IPv4 ID 0xbeef in fragments.pcap contains overlapping fragments that overwrite earlier bytes.…
CryptographyLevel 5★★★★★Cryptanalysis - RSA e=3 Broadcast Attack
broadcast.json contains the same plaintext encrypted with unpadded RSA e=3 under three pairwise-coprime moduli.…