Understanding Cryptography

Not repeating the WWII mistakes

Although cryptography has been increasing rapidly over the last few years, it can be a complicated and confusing subject to anyone not familiar with it. If cryptography sounds new, don't worry because after reading this article, you'll have a basic knowledge of it.

You will know what cryptography is, its components, features, types, and the problems it solves. Understanding cryptography today is quite essential, for it has incredible benefits when used.

What is Cryptography?

Cryptography is a technique that secures communications and information through encryption and decryption of messages to avoid unintended interruption. It helps hide information from an opponent or enemy who might seize them, with its numerous techniques that safeguard data in an unreadable format.

Some of the cryptographic techniques are adopted in securing electronic transactions like credit card details, E-mail messages, storage media, video/audio broadcasting, or any other sensitive information. Cryptographic systems allow one to encrypt a message before passing it on the network. On the other hand, the recipient decrypts the message to get its original content.

Components of Cryptography

  • Plaintext: This is an ordinary readable binary code, text, or an image before it has been encrypted or simply converted into an unreadable format. It's an unmodified message that one wishes to send.
  • Ciphertext: In simple terms, it's a text that cannot be read because it has undergone through the encryption process. The ciphertext is an encrypted message the recipient receives.
  • Encryption: It's a process that transforms readable information into an unreadable format that is reversible. For a better understanding, encryption turns plaintext into ciphertext using an algorithm called a secret key and a cipher. No one can view a piece of encrypted vital information without the secret key.
  • Decryption: This reverses the encryption process by transforming the ciphertext back to plaintext using a secret key and a decryption algorithm.
  • Ciphers: Ciphers refer to encryption and decryption algorithms. It's a formula that illustrates how to implement the encryption and decryption process on certain information.
  • Key: It's basically a single number or a series of numbers in which the cipher operates. A key is usually responsible for controlling ciphertext and plaintext outputs. A good example of a key is when a sender uses it to encrypt a message before sending it, and the recipient uses it to decrypt the received signal.

Features of cryptography

  1. Authentication: Both sender and recipient identities are confirmed, as well as the source and destination of the information.
  2. Integrity: When the information is in transition between the sender and intended receiver, it cannot be altered without being detected.
  3. Confidentiality: Only the intended person can access the information sent; no other person can access it.
  4. Non-repudiation: The one who has sent information cannot deny their intention for the action later.

Types of Cryptography

Cryptography is categorized into three types, as discussed below:

  • Symmetric key Cryptography: This is also known as secret or private key cryptography. It is an encryption system that allows both message sender and receiver to use the same key to encrypt and decrypt the message. Even though this type of cryptography is simpler and simpler, exchanging the key between the sender and receiver in a secure manner can be problematic. Some examples of symmetric key cryptography include IDEA, DES (Data Encryption System), Block, RC2, Block cipher, Blowfish, Block, and Stream cipher.
  • Hash functions: This is a mathematical equation that takes numerical values as input and gives a hash message. No key is used in this type of algorithm, making it impossible to recover plaintext contents. For that reason, hash functions are mostly used in encrypting passwords. Some of its functionalities are SHA (Secure Hash Algorithm), Message Digest 5 (MD5), Whirlpool, and RIPEMD.
  • Asymmetric Key Cryptography: This is also referred to as public-key cryptography. It uses a varied and secure method while transmitting the information. Under this technique, data is encrypted and decrypted using two different keys: a private key for decryption and a public key for encryption.  The private key is kept by each person, while the public key is shared across a network. Types of Asymmetric key cryptography include DSA, RSA, Elliptic curve techniques, and PKCS.

Applications of cryptography

As a secure system, cryptography solves several problems, aside from assuring integrity, confidentiality/privacy, non-repudiation, and data availability. For instance, cryptography helps in protecting communications that cross untrusted networks with possible attacks. Systems are vulnerable to two main types of attacks: Active attacks and passive attacks.

Active attacks are when an invader intercepts communications in transit, views it, and modifies the content before reaching the rightful person. On the contrary, passive attacks involve an invader only listening on a network without changing anything. With cryptography, none of these attacks can take place on a system. So, it's completely reliable in all transmissions.

It can also be used to secure stored data. You can encrypt data on a removable disk or in a database to avoid the leak of vital information if you lose the physical media. Cryptography maintains secrecy of that data, and not even hackers can access it. Besides that, it offers integrity protection of the stored data to detect any malicious interference.

Final verdict

In this era and modern schemes, data encryption is the way to go. Hackers and eavesdroppers are doing all they can to access protected data, but with cryptography is your information beyond their reach. It has great techniques and algorithms to make your personal data more secure with its highly reliable standards.