What is "decyphered"

Usage examples of "decyphered".

I am writing in that broken cypher to d’Avaux in Holland on the assumption that everything I write will be decyphered and read by the Dutch.

As well she carries on a steady flow of correspondence to certain Jews of Amsterdam, consisting predominantly of numbers and financial argot that, read, cannot be decyphered, and decyphered, cannot be understood, unless one is familiar with the workings of that city’s commodities markets, as vulgar as they are complex.