Currently, the term cipher is commonly used to refer to encrypted messages. However, five centuries ago, it actually meant “zero”. This shift in meaning occurred as it became associated with numerals in general, then with codes utilizing numerals, and eventually evolved into its modern definition. The term originates from Old French cifre, Latin cifra, and ultimately Arabic sifr, which originally meant “zero”. Due to the absence of the concept of nothingness in the Roman numeral system, sifr also contributed to the word for “zero” in numerous European languages such as French chiffre, German ziffer, and English zero. This term is believed to have derived from an earlier Arabic term, safara, meaning “to be empty”. The etymology of safara is intriguing as it is named after the Arabic month of Safar, the second month of the Muslim calendar, which was infamous for pagan raids that left homes vacant.
