Shihāb al-Dīn Abū 'l-Abbās Aḥmad ibn ‘Alī ibn Aḥmad ‘Abd Allāh
al-Fazārī al-Shāfiʿī better known by the
epithet
An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...
al-Qalqashandī ( ar, شهاب الدين أحمد بن علي بن أحمد القلقشندي; 1355 or 1356 – 1418), was a medieval
Egyptian encyclopedist,
polymath and
mathematician. A native of the
Nile Delta
The Nile Delta ( ar, دلتا النيل, or simply , is the delta formed in Lower Egypt where the Nile River spreads out and drains into the Mediterranean Sea. It is one of the world's largest river deltas—from Alexandria in the west to Po ...
, he became a Scribe of the Scroll (''Katib al-Darj''), or clerk of the
Mamluk chancery in
Cairo,
Egypt. His
magnum opus is the voluminous administrative encyclopedia ''Ṣubḥ al-Aʿshá''.
''Ṣubḥ al-aʿshā''
''Ṣubḥ al-Aʿshá fī Ṣināʿat al-Inshāʾ'' ('The Dawn of the Blind' or 'Daybreak for the Night-Blind regarding the Composition of Chancery Documents'); a fourteen-volume encyclopedia completed in 1412, is an administrative manual on geography, political history, natural history, zoology, mineralogy, cosmography, and time measurement. Based on the ''Masālik al-abṣār fī mamālik al-amṣar'' of
Shihab al-Umari, it has been called "one of the final expressions of the genre of
Arabic administrative literature".
Selections on "Seats of Government " and "Regulations of the Kingdom " from Early Islam to the Mamluks' have been published separately.
The ''Ṣubḥ al-aʿshā'' was cited by
David Kahn as the first published discussion of the substitution and transposition of ciphers, and the first description of a
polyalphabetic cipher
A polyalphabetic cipher substitution, using multiple substitution alphabets. The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case. The Enigma machine is more complex but is sti ...
, in which each
plaintext letter is assigned more than one substitution. The exposition on cryptanalysis included the use of tables of
letter frequencies and sets of letters which cannot occur together in one word.
Kahn therefore cited it as the first work in human history that described cryptology, because it described both cryptography and cryptanalysis. Al-Qalqashandi quoted the text relevant to cryptology from the work of
Ibn al-Durayhim (1312–1361) that was once considered lost. Later discoveries in Istanbul‟s Sulaimaniyyah Ottoman Archives did not just find the work by Ibn Duraihim, but also works of
al-Kindi in the 9th century that is now considered the oldest work on cryptology.
[Kathryn A. Schwartz (2009): Charting Arabic Cryptology's Evolution∗, ''Cryptologia'',33:4, 297-304 ]
References
Sources
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External links
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Further reading
*''Christian and Jewish Religious Dignitaries in Mamluk Egypt and Syria: Qalqashandi's Information on their Hierarchy, Titulature, and Appointment (I &II)'' ''
International Journal of Middle East Studies'', 3:1, 3:2 (1972)
1350s births
1418 deaths
14th-century Arabs
15th-century Arabs
14th-century Egyptian people
14th-century mathematicians
15th-century Egyptian people
15th-century mathematicians
Egyptian encyclopedists
Egyptian scientists
Medieval Egyptian mathematicians
Scholars from the Mamluk Sultanate
Encyclopedists of the medieval Islamic world
Pre-19th-century cryptographers
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