Use "secret writing" in a sentence

1. There was also Nostradamus’s secret writings to consider, and the Mayan long count calendar, calculated to end after 5125 years, on the 21st December 2012

2. I am fairly familiar with all forms of secret writings, and am myself the author of a trifling monograph upon the subject, in which I analyze one hundred and sixty separate ciphers; but I confess that this is entirely new to me

3. "Having once recognised, however, that the symbols stood for letters, and having applied the rules which guide us in all forms of secret writings, the solution was easy enough

4. I am fairly familiar with all forms of secret writings, and am myself the author of a trifling monograph upon the subject, in which I analyze one hundred and sixty separate ciphers, but I confess that this is entirely new to me

5. "Having once recognized, however, that the symbols stood for letters, and having applied the rules which guide us in all forms of secret writings, the solution was easy enough