The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.
... that the early cryptologistIbn 'Adlan worked as a teacher of Arabic at Al-Salihiyya Mosque in Cairo (complex pictured in 2015)? Source: "Then he taught Arabic language for a while and had many students. He had his class in the as-Salih Mosque in Cairo... (Mrayati, Meer Alam & at-Tayyan 2004, p. 13)"
ALT1:... that the Arab cryptologistIbn 'Adlan wrote about the cryptanalysis of ciphers with no space symbol, three centuries before it was first done in the West by G. B. Porta? Source: "This led to encipherment with no space symbol between word or with multyple symbols to represent the space symbol, methods that al-Kindi never faced. ibn 'Adlan shows how to break such ciphers ... This was three centuries before encipherment without spaces was treated in the west by the Italian cryptanalyst, G. B. Porta. (Massey 2008, p. 281)"