{"enrichment":{"faq":[{"a":"symmetric-cipher-attacks teaches how padding oracle vulnerabilities work in CBC mode. When a server leaks whether padding is valid or invalid, attackers can decrypt ciphertext byte-by-byte without the key. The skill covers the mechanics of manipulating ciphertext blocks, observing server responses, and reconstructing plaintext through iterative guessing. Tools like PadBuster automate this process for authorized testing.","q":"What is a CBC padding oracle attack tutorial for symmetric-cipher-attacks?"},{"a":"symmetric-cipher-attacks demonstrates that ECB encrypts identical plaintext blocks to identical ciphertext blocks, leaking patterns. The skill teaches detection methods (spotting repeated ciphertext), exploitation techniques (byte-at-a-time decryption), and why ECB should never be used. Practical examples show how to recover plaintext from ECB-encrypted data without the key through systematic block manipulation.","q":"How does symmetric-cipher-attacks explain ECB mode weaknesses?"},{"a":"symmetric-cipher-attacks covers multiple decryption techniques that don't require the original key. These include padding oracle attacks on CBC, ECB block-by-block recovery, stream cipher key reuse exploitation via XOR, and state recovery attacks on LFSRs and RC4. Each method targets specific cipher modes or implementation flaws rather than breaking the cipher mathematically.","q":"Can symmetric-cipher-attacks help decrypt data without the key?"},{"a":"symmetric-cipher-attacks teaches key reuse vulnerabilities in stream ciphers, where XORing two ciphertexts encrypted with the same keystream reveals plaintext patterns. The skill covers two-time pad attacks, Kasiski examination for repeating keys, RC4 bias attacks for plaintext recovery, and LFSR state recovery through cryptanalysis. Python implementations demonstrate practical exploitation.","q":"What stream cipher attacks does symmetric-cipher-attacks include?"},{"a":"symmetric-cipher-attacks is designed for both CTF cryptography challenges and authorized penetration testing. It covers block cipher mode attacks, stream cipher breaks, and cryptanalysis techniques used in competitions. The MIT license permits educational and professional use. The skill emphasizes hands-on Python implementations and tool usage for legitimate security assessment scenarios.","q":"Is symmetric-cipher-attacks suitable for CTF and authorized testing?"}],"shadow_tags":["block-cipher-exploitation","padding-oracle-vulnerability","stream-cipher-weakness","mode-of-operation-attack","cryptanalysis-techniques","key-recovery-method","ctf-crypto-challenge","penetration-testing-crypto","ciphertext-manipulation","prng-state-recovery"],"summary_rewrite":"This skill covers hands-on cryptanalysis of symmetric encryption vulnerabilities across block and stream ciphers. Learn to exploit CBC padding oracles and bit flipping attacks, detect and abuse ECB mode repetition, decrypt data byte-at-a-time, and break stream ciphers through key reuse and state recovery. Includes Python implementations and tool usage for authorized testing and CTF challenges."},"files":[{"bytes":14622,"path":"skills/symmetric-cipher-attacks/SKILL.md","sha256":"892f990cf51ff722dad68050219b55086a60e7085ff6d4ad191003f8fcc94d24","url":"https://skillfed.io/files/yaklang/hack-skills/symmetric-cipher-attacks/c52127d0/SKILL.md"}],"id":"yaklang/hack-skills/symmetric-cipher-attacks","links":{"html":"https://skillfed.io/yaklang/hack-skills/symmetric-cipher-attacks","md":"https://skillfed.io/yaklang/hack-skills/symmetric-cipher-attacks.md","repo":"https://github.com/yaklang/hack-skills"},"meta":{"agents_supported":[],"first_seen":"2026-07-28","forks":196,"language":"CSS","last_updated":"2026-06-16","license":"MIT","name":"symmetric-cipher-attacks","publisher":"yaklang","stars":1480},"relations":{"similar":[{"id":"ljagiello/ctf-skills/ctf-crypto"},{"id":"yaklang/hack-skills/classical-cipher-analysis"},{"id":"Unclecheng-li/VulnClaw/ctf-crypto"},{"id":"hypnguyen1209/offensive-claude/crypto-analysis"},{"id":"cyberkaida/reverse-engineering-assistant/ctf-crypto"},{"id":"martinholovsky/claude-skills-generator/encryption"},{"id":"Unclecheng-li/VulnClaw/crypto-toolkit"},{"id":"yaklang/hack-skills/rsa-attack-techniques"},{"id":"wshaddix/dotnet-skills/dotnet-cryptography"},{"id":"Unclecheng-li/VulnClaw/redteam-crypto-detail-pack"}]},"slug":{"owner":"yaklang","repo":"hack-skills","skill":"symmetric-cipher-attacks"},"version":"c52127d0"}