Frequency analysis
Análisis de frecuencias en criptoanálisis
- Date
- c. 850 · confidence medium
- Place
- Baghdad, Iraq
- Credited to
- Al-Kindi
- People
- 👤 Al-Kindi801–870
- Field
- Knowledge & symbols
What was discovered
A method for breaking substitution ciphers by comparing the frequency of symbols with that of the letters of the language. The first documented use of applied statistics.
Described in the Manuscript on Deciphering Cryptographic Messages, rediscovered in 1987.
What it led to
- modern cryptanalysis
- descriptive statistics
- information theory
Built on
- substitution ciphers
- linguistic studies of the Quran
Made possible
- diplomatic code-breaking