Baghdad. Islamic civilization was sufficiently advanced in the disciplines necessary to develop advanced encryption and decryption techniques: mathematics, statistics, and linguistics. To develop knowledge (“ilm”). In 815, Caliph al-Mamun established the Bait al-Hikmah (the House of Wisdom) in Baghdad, a library and translation center, with thousands of books in Egyptian, Babylonian, Indian, Chinese, Farsi, Syriac, Armenian, Hebrew, and Latin, all translated into Arabic. Also in the 9th century, the scientist Abu Yusuf Qub ibn Is-haq ibn as-Sabbah ibn Omran ibn Ismail al-Kindi (or simply al-Kindi) authored 290 books on medicine, mathematics, linguistics, and music, and developed a decryption technique based on the frequency of letters in different languages.
