ctf-crypto

Identifying cryptographic implementations in a binary involves analyzing constant arrays and round counts to classify the algorithm class as block, stream, or hash. This process spots where crypto is used and determines the exact algorithm type for further analysis.

Tracing hardcoded keys involves following derived keys through execution code paths to locate key material sources. By tracking these data flows, you can pinpoint exact key locations and establish a reproducible decryption plan to recover the target flag.

Exploiting weak crypto implementations involves identifying vulnerabilities like weak RNGs or ECB weaknesses in custom ciphers and proposing targeted exploitation strategies. This weakness discovery process outlines how to extract keys or decrypt data by leveraging implementation flaws.

Yes, you can find cryptographic backdoors or exfiltration vectors in CTF binaries by analyzing the implementation for hidden weaknesses and potential data exfiltration paths. This analysis provides concrete evidence of how data is decrypted or extracted.

Creating a reproducible decryption plan involves combining identified algorithm classes, traced key locations, and discovered implementation weaknesses into a step-by-step strategy. This plan uses extracted key material to successfully decrypt the data and recover the flag.