Ahmad al-Qalqashandi

Shihab al-Din abu 'l-Abbas Ahmad ben Ali ben Ahmad Abd Allah al-Qalqashandi (1355 or 1356 – 1418) was a medieval Egyptian writer and mathematician.

Born in a village in the Nile Delta, al-Qalqashandi was scribe of the scroll (katib al-darj) in the Mamluk chancery in Cairo. He is the author of Subh al-a 'sha, completed in fourteen volumes in 1412, "one of the final expressions of the genre of Arabic administrative literature".^[1]

The Subh al-a 'sha included a section on cryptology. This information was attributed to Ibn al-Durayhim who lived from 1312 to 1361, but whose writings on cryptology have been lost. The list of ciphers in this work included both substitution and transposition, and for the first time, a cipher with multiple substitutions for each plaintext letter. Also traced to Ibn al-Durayhim is an exposition on and worked example of cryptanalysis, including the use of tables of letter frequencies and sets of letters which can not occur together in one word.

References

1. ↑ Maaike van Berkel (2009). "al-QALQASHANDĪ". In Roger M. A. Allen; Terri DeYoung. Essays in Arabic Literary Biography II: 1350-1850. Otto Harrassowitz Verlag. pp. 331–40. ISBN 978-3-447-05933-6. Retrieved 30 March 2013. 

External links

• Qalqashandī, Aḥmad ibn ʻAlī (1879). Die Geographie und Verwaltung von Ägypten. Translated by Ferdinand Wüstenfeld. 
• Qalqashandī, Aḥmad ibn ʻAlī (1903). Ṣuhḥ al-aishā. 

Arabic Wikisource has original text related to this article: Ahmad al-Qalqashandi

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)

Mathematics in medieval Islam
Mathematicians (Works)	9th century 'Abd al-Hamīd ibn Turk Sind ibn Ali Al-Abbās ibn Said al-Jawharī Al-Ḥajjāj ibn Yūsuf ibn Maṭar Al-Kindi De Gradibus Al-Mahani Banū Mūsā Hunayn ibn Ishaq al-Khwārizmī The Compendious Book on Calculation by Completion and Balancing ibn Qurra Na'im ibn Musa Sahl ibn Bishr Habash al-Hasib al-Marwazi 10th century Abd al-Rahman al-Sufi Book of Fixed Stars al-Būzjānī Abū Ja'far al-Khāzin Abū Kāmil Shujāʿ ibn Aslam Abu'l-Hasan al-Uqlidisi Abu-Mahmud Khojandi Ahmad ibn Yusuf Al-Nayrizi Al-Saghani Brethren of Purity Ibn Sahl Ibn Yunus Ibrahim ibn Sinan Muhammad ibn Jābir al-Harrānī al-Battānī Sinan ibn Thabit Al-Isfahani Nazif ibn Yumn Abū Sahl al-Qūhī 11th century Abū Ishāq Ibrāhīm al-Zarqālī Abu Nasr Mansur Abū Rayḥān al-Bīrūnī Ibn al-Haytham / Alhazen Book of Optics Ibn Muʿādh al-Jayyānī Al-Karaji Al-Sijzi Alī ibn Ahmad al-Nasawī Avicenna The Book of Healing Ibn Tahir al-Baghdadi Kushyar ibn Labban Yusuf al-Mu'taman ibn Hud 12th century Al-Khazini Ibn Yahyā al-Maghribī al-Samaw'al Omar Khayyám Jabir ibn Aflah Abu Bakr al-Hassar 13th century Muhyi al-Dīn al-Maghribī Nasīr al-Dīn al-Tūsī Zij-i Ilkhani Shams al-Dīn al-Samarqandī Sharaf al-Dīn al-Tūsī Ibn al‐Ha'im al‐Ishbili Ibn Abi al-Shukr 14th century Yaʿīsh ibn Ibrāhīm al-Umawī Ibn al-Banna' al-Marrakushi Ibn al-Shatir Kamāl al-Dīn Fārisī Al-Khalili Qotb al-Din Shirazi Ahmad al-Qalqashandi 15th century Abū al-Ḥasan ibn ʿAlī al-Qalaṣādī Ali Qushji Jamshīd al-Kāshī Qāḍī Zāda al-Rūmī Ulugh Beg Ibn al-Majdi 16th century Al-Birjandi Muhammad Baqir Yazdi Taqi al-Din Ibn Hamza al-Maghribi Ibn Ghazi al-Miknasi
Other treatises	Almanac Encyclopedia of the Brethren of Purity Tables of Toledo Tabula Rogeriana Zij Zij-i-Sultani
Concepts	Alhazen's problem Islamic geometric patterns
Centers	Al-Azhar University Al-Mustansiriya University House of Knowledge House of Wisdom Istanbul observatory of Taqi al-Din Madrasah Maktab Maragheh observatory University of Al-Karaouine
Influences	Babylonian mathematics Greek mathematics Indian mathematics
Influenced	Byzantine mathematics European mathematics Indian mathematics