Smithy cipher
Please note that these tools aren't optimized for large amounts of data, processing can slow down or run into problems once you reach above 150,000 characters. A cap of 1 million characters is currently in place.
Smithy cipher
Smithy is interesting cipher, built using the fibonacci sequence as part of the keyword ecryption/decryption process. It was originally made for private amusement, and included in documentation in The Da Vinci Code copyright case. For example:
Hello encrypted with a key of World would shift like:
Rmxsp
There is more information available on the Smithy Wikipedia page
Smithy cipher