Transcription of Encoded Manuscripts with Image Processing Techniques
Historical hand written manuscripts are an important source of information for our cultural heritage, and automatic processing of these can help exploring their content faster and easier. A special type of hand written manuscripts that are relatively common in archives and libraries are encrypted, secret documents, so called ciphers. Ciphers may contain and hide important information for the history of science, religion or diplomacy and therefore shall be decrypted and made accessible. The automatic decryption of historical hand written ciphers is the main focus of the project DECODE: Automatic decoding of historical manuscripts. In order to reveal the content of these secret messages, we collect and digitize ciphertexts and keys from Early Modern times, build a database, and develop software tools for (semi )automatic decryption by crossdisciplinary research involving computer science, language technology, linguistics and philology. Ciphers use a secret method of writing, often by transposition or substitution of characters, special symbols, already existing alphabets, digits, or a mixture of these. The encoded sequences are usually meticulously written and often segmented character by character to avoid any kind of ambiguity for the receiver to be able to decode the content, but continuous writing of some sequences where the symbols are connected also exists. In addition, the cipher sequences might be embedded in cleartext, i.e. texts in a known natural language, as illustrated in the picture below (Archivio Segreto Vaticano, 2016)
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