The use of secret codes or ciphers became popular during World War II. Passwords are very important because any information needs to be kept confidential from enemies. There is a versatile scientist named Al Kindi behind this.
Al Kindi not only gave birth to ideas in the field of philosophy. Quoted from the KESAN Islamic application, Tuesday (11/4/2022) Al Kindi was the first person to successfully develop a cryptanalysis theory. The book describes and discusses cryptology or the art of breaking codes. In his book, Al Kindi describes how secret codes are deciphered.
"One way to crack the secret code, if we know the language, is to find a different original script from the same language, then we count the events in each script into a script of occurrence one, event two, and so on," said Al Kindi.
After that, continued Al Kindi, only then did he look at the secret text he wanted to solve, then proceed with classifying the symbols.
There, we will find the symbols that appear most often. Then the symbol is changed with a record of events one, two, and so on until all symbols are read.
The technique came to be known as frequency analysis in cryptography, which is the simplest way to calculate the percentage of specific language in the original text, the percentage of letters in the secret code, and replace symbols with letters.
For example, in Indonesian the letter that appears most often is the letter 'a'. This way, the replacement letter 'a' will appear the most in the sentence, so the actual word is predictable. So what needs to be ensured is only the language used in the code message.
Al Kindi was inspired to develop this theory after studying the words in the Qur'an. The term cryptanalysis itself only emerged in the 20th century, but the basic theory was compiled by Al Kindi 9 centuries ago.
Al Kindi mastered cryptography, because he was an expert in the field of Mathematics. In this area of knowledge, he wrote four books on the numbering system and formed the basis for modern arithmetic. Al Kindi also contributed greatly to the field of spherical geometry, a field that greatly supported him in the study of astronomy.
Working in the field of secret ciphers and hidden messages in the original Greek and Roman manuscripts, has sharpened his instincts in the field of cryptanalysis.