The Ultimate Guide to Cryptography

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Cryptography is the process of using different types of codes to encrypt data. These codes act as a protective bubble around the data during transmission, they will be useless because they are undecipherable.

The process starts with unencrypted data called the plaintext. Then, it will be encrypted and become a ciphertext. Lastly, the information will be decrypted and become plaintext again. The process of encryption and decryption involves the use of a key.

Although cryptography has become popular these days because of blockchain technology, the concept is not new. Experts surmise that cryptography was invented together with writing. The most popular form of ancient cryptography is the Egyptian hieroglyphs.

Today, cryptography has five primary functions:

  • Confidentiality – no one can access/read the data except the receiver.
  • Authentication – you can prove the identity of both parties.
  • Non-repudiation – the sender cannot deny that he is the author/owner.
  • Integrity – the information wasn’t tampered or altered on or during transmission.
  • Key exchange – the process where the sender and receiver share crypto keys.

Types of Cryptographic Algorithms

The number of keys used during encryption and decryption classifies cryptographic algorithms.

There are three primary types of cryptographic algorithms:

Secret Key Cryptography (SKC)

Also called symmetric encryption, where only a single key is used to encrypt and decrypt the data. The sender uses the key to encrypt the data and sends it to the receiver. With the same key, the receiver decodes the data so he can read the information. Thus, both the sender and the receiver should know what the key is.

Public Key Cryptography (PKC)

This algorithm uses a key pair so both parties can have secure communication even in a non-secure channel. Each person has their pair of keys – a public key and a private key. The process starts with the sender encrypting the information he is going to send using his private key and the receiver’s public key. The receiver, on the other hand, decrypts the message using his private key and the sender’s public key.

Hash Functions

This type of algorithm does not use any key at all. Instead, it uses one-way encryption and is primarily used to ensure the authenticity and integrity of the information.

Different Applications of Cryptographic Algorithms

Some of the encryptions below are being used by a lot of people either knowingly or unknowingly to keep their data protected and ensure secure communication.

Challenge Handshake Authentication Protocol (CHAP)

This encryption allows a person to prove his identity to another through a shared secret without listeners knowing what the secret is.

Federal Information Processing Standards (FIPS)

Released by the U.S. National Institute of Standards and Technology, this is the standard encryption used by the US government.

Private Communication Technology (PCT)

This encryption is used for secure communication over the Internet. It was developed by Microsoft and supports RSA, Diffie-Hellman, and Fortezza for key establishment. However, it failed to gain a lot of popularity and has been overtaken by TLS and SSL.

Secure Electronic Transaction (SET)

This communication protocol was developed jointly by MasterCard and Visa together with RSA, Microsoft, and IBM. It is used to secure credit card transactions over the Internet.

Secure Sockets Layer (SSL)

This type of encryption provides privacy and application-independent security on the Internet. However, the Internet Engineering Task Force or IETF has scratched it in favor of Transport Layer Security or TLS.

Simple Key Management for Internet Protocol (SKIP)

It is used to secure IP connections between a pair of Internet hosts using X.509 certificates. It can employ 3DES, DES, SHA-1, and IDEA. However, it hasn’t gained enough traction because of the Internet Key Exchange (IKE).

IP Security Protocol (IPsec)

This type of algorithmic encryption authentication provides privacy for all communications happening on the Internet.


The information here is just part and parcel of cryptography. There are still a lot of cryptographic applications used in our daily lives and more complex environments. Although they are many, they serve a common purpose of creating a secure and safe exchange of information in the digital world.

PS: If you are interest on the topic and would like to know more about it, check out our blog post about digital signatures and how they work!

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