<p>Sent by a Spanish diplomat. Apparently people have been <a href="https://www.medievalists.net/2026/04/secret-letter-detailing-late-medieval-britain-fully-decoded/">working on it</a> since it was rediscovered in 1860.</p>
OSINT & Intelligence
Historic Cipher Broken: Diplomatic Secrets of Medieval Spain Revealed
- Centuries-old diplomatic letter from a Spanish envoy finally decrypted.
- The complex cipher remained unbroken since its rediscovery in 1860.
- Unlocks historical intelligence on late medieval Britain and Spanish diplomacy.
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Intelligence briefing: Why this matters: This historic decryption underscores the enduring challenge of cryptanalysis and the long-term value of intelligence, offering lessons relevant to modern secure communications and data recovery.