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Currently making the solution for NSA Backdoor and the walkthrough will be published here as soon as it's ready.
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NSA Backdoor
Published: July 20, 2023Updated: December 9, 2025
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Useful tools for Cryptography
- ROT / Caesar CipherDecode Caesar-shifted and ROT-encoded text. Drag the shift slider or scan all 26 rotations at once.
- Base64 & Base32 DecoderDecode Base64 and Base32 strings with auto-detection. Multi-layer mode unwraps nested encodings automatically.
- XOR CipherXOR-decrypt hex or text ciphertext with a known key, or brute-force the single-byte key automatically.
- Vigenère CipherEncrypt or decrypt text with the Vigenère polyalphabetic substitution cipher using a keyword.
More Cryptography
- CryptographyMedium
basic-mod1
Take each integer mod 37 and map it to a custom A-Z/digit/underscore alphabet to decode the flag.
- CryptographyMedium
basic-mod2
Compute the modular inverse of each value mod 41, then map to the custom alphabet to decode the flag.
- CryptographyMedium
credstuff
Find 'cultiris' in a leaked credential dump, decode the ROT13-encoded password, and submit it as the flag.