Coded messages and mysteries have fascinated me from childhood.
I landed across this fascinating method of coding numbers in the form of poems in this video. The method used is a simple number-to-letter mapping technique.
Consider this shloka (Sanskrit verse):
खलजीवितखाताव गलहालारसंधर ॥
This is a simple verse apparently in the praise of Lord Krishna. Here is the meaning..
O Lord anointed with the yogurt of the milkmaids’ worship (Krishna),
O savior of the fallen, O master of Shiva, please protect me.
(I would request any Sanskrit experts to shine a light on the meaning of each word)
A simple system is used called the Katapayadi System. Here, क(ka) is 1, ख(kha) is 2,ग(ga) is 3, घ(gha) is 4 and so on..
Applying this, we get the value: 3.1415926535897932384626433832792 which is the value of Pi upto 31 decimal places. My mind was blown at this clever encryption into a poem!
I did the decryption myself to cross-check and it matches.
These encryption techniques date back upto 700 CE in India.