Una of the oldest techniques used to protect information is the cryptography. This technique is as old as writing. And one of the many examples that we find about its use is the interesting case of the history of the Enigma machine, used by the Nazis during World War II to encrypt messages on the battlefront.
The word cryptography comes from the Greek κριπτός (kryptós = covered, hidden), γραφειν (grafein = write), and the suffix -ia (used to create abstract nouns). The encrypted message itself is in plain view. It can be read, but its meaning is hidden. Thus, we can say that through cryptography a person can hide a text or information, so that only the sender and receiver can interpret it.
With the increasing boom and development of computing, it was widely disclosed and modified for its use. Now it is based on complex mathematical algorithms that are responsible for encrypting messages. They are tasked with ensuring confidentiality between the parties and the integrity of the information. At the same time that it offers the authentication of both the sender and the receiver, it guarantees that the sender or receiver can repudiate the message. And finally, it guarantees that the message is new, that is, that it is not repeated.
The foundations of computer cryptography are established in the articles "A Mathematical Theory of Communication" of 1948 and "Communication Theory of Secrecy Systems" 1949. Both published by Claude Shannon that lay the foundations of information theory and modern cryptography.
"New directions of Crytography", Developed by Whitfiled Diffie and Martin Hellman in 1976 establishes the concept of public key cryptography. Crypto consolidation comes in 1977 with the publication of the RSA algorithm, developed by mathematicians Ron Rivest, Adi Shamir y Len Adleman.
Cryptography and security
Nowadays, cryptography is one of the fundamental pillars on which technology is based blockchain. This allows the operation of the network, guarantees the mechanisms of consent between users and the integrity of the blockchain.
To guarantee that no external person can access the data, the cryptography of public key (asymmetric cryptography) and secret key cryptography (symmetric cryptography) that we will develop later. Public key encryption generates a hash which makes the distribution of information easier while the private key encrypts and decrypts information between sender and receiver.
En Bitcoin, the public key is obtained using the private key, but the reverse process is impossible to perform. That is to say, unable to get private key from public key. The public key, after some subsequent modifications, is the address that we can share with all members of the community so that they send us money. Or in your case, the one that we will use from other users of the community to make some payment. There is no risk of theft, since the funds are only accessible through the private key.
The private key is similar to a PIN or password that we use to access different web pages, but in this case it is encrypted, adding much more security. This means that we will introduce a series of terms or words and these will be encrypted and protect the wallet or purse. Only we have these words, so we must keep them safely and not share them with anyone. This way we can access our funds at any time.