Ibn 'Adlan

ʻAlī ibn ʻAdlān (Arabic: علي بن عدلان‎‎; 1187–1268 CE) was born in Mosul and is best known for his early contributions to cryptanalysis for which he dedicated more than one book. He was also involved in literature and poetry.

Ibn 'Adlan was educated in Baghdad and lived in Damascus and Cairo.

His two major works on cryptanalysis were Al-mu'lam and Al-mu'allaf lil-malik al-'Asraf. One of his most important contributions was on sample size for use of frequency analysis. He believed that the cryptogram "should be at least 90 letters long and that each of the 28 letters of Arabic should be represented at least three times".

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