As an English author but long time resident of America, I recently wrote a historical spy thriller that delved deeply into coded messages. I often caught myself writing cipher and cypher. Although I eventually used cipher exclusively the plot was mainly located in England and France.
Would cypher have been a better choice?
Best Answer
This isn't strictly an "answer", but I thought you would be interested to see this pot-pourri of spellings of cipher/cypher from the 16th century onwards. It is from sense 5 of the word cipher/cypher in the Oxford English Dictionary. Of course the word began life from the French cuffre (modern French chiffre) with an entirely different meaning (the figure, nought) in the 14th century.