Partial substitution font
The partial substitution script is a - not particularly secure - cryptographic method that was used in numerous medieval manuscripts from the 9th century, for example in the Trier verse .
With the bfk cipher variant , the vowels are replaced by the next consonant (of the classical Latin alphabet ). Instead of "a" you write "b", "e" is replaced by "f", "i" by "k", "o" by "p", and "u" by "x". All consonants remain unchanged. The name of the encryption is derived from the first three conversions. A variant of the bfk cipher is the cgl encryption, in which the vowels are replaced by the consonant after the next. This cipher apparently did not have the character of data encryption, but rather was used in a playful way, because it is easy to decipher.
A fictional example of bfk encryption: "New moon ascent" becomes "Nfxmpndbxfstkfg" in the ciphertext.
Because of the lack of uniqueness (double occupancy of the consonants), it cannot be compared with the Caesar encryption .
The first documentary mention is said to be around 800 - 850 AD. as the oldest script, its heyday of gloss cryptography was in the 10th and 11th centuries.
literature
- Stephan Müller , Secret documents of the Middle Ages Online: University of Paderborn ( PDF file; 199 MB)
Individual evidence
- ↑ a b Trier Verse , historical manuscript with bfk and cgl secret script from the Trier City Library
- ↑ Stephan Müller: Secret Scripts of the Middle Ages (Online via Google) ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
