CTF Bench
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Keyed Grid

crypto medium 200 pts 0 solves ctfbench-006
A 5x5 keyed Polybius grid is constructed from the keyword `MERCURY` then the rest of the<br/>alphabet (I/J combined). Coordinates are row/col starting at 1.<br/><br/>Ciphertext coordinates:<br/><br/>```<br/>23 15 11 11 34 51 24 42 11 31<br/>```<br/><br/>Decode to letters. Flag: `CTFBENCH{<decoded_lowercase>}`<br/>

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