Cryptography
https://en.wikipedia.org/wiki/Cryptography
Cryptography or cryptology is the practice and study of techniques for secure communication in the presence of third parties called adversaries.
(from Greek κρυπτός kryptós, "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively[1])
I didn't knew about cryptography before.thanks for sharing☺
Bitcoin IS Cryptography! Read up
As far as I knew cryptography is a process of storage of data and transmission of data in a particular form so that only those for whom it is intended can read and process it.