What Is Cryptography?

Cryptography is the study of secure communication methods that enable only the sender and the intended recipient to view a message’s content.

Written by Anthony Corbo
Published on Dec. 16, 2021
What Is Cryptography?
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This ensures no outside parties will be able to intercept and compromise the message’s integrity. Cryptography is closely related to encryption, which scrambles a message into ciphertext that must be decoded by the recipient with a key. Cryptography also covers the obscuring of images through steganography, or the practice of hiding malicious messages within an image.

What is cryptography used for?

Cryptography is used to provide secure communications when transferring data and messages to avoid malicious third-party interception.

Cryptography exists to ensure that messages can be exchanged between parties in a secure manner. Cryptography is a continuously evolving study, growing and adapting as technology evolves and the cybersecurity landscape changes. The most widely-used form of cryptography is encryption, which uses an algorithm and a matching key to transform an input, such as plaintext, into an encrypted output known as ciphertext. Any algorithm will produce the same ciphertext when the same input is provided and the same key is used to decrypt. Without knowledge of the plaintext or the encryption key, it is much more difficult for a malicious individual to intercept and view the information passed between parties.

Effective cryptography focuses on four key objectives: confidentiality, which ensures that only the intended recipient can decode and read the message; non-repudiation, which stops a sender from denying a message was sent or received; integrity, which ensures the contents of the message cannot be modified while being transmitted or stored; and authenticity, which ensures the sender and receiver can verify each other’s identities and the message reaches its intended destination.

What are the three types of cryptography?

The three forms of cryptography include symmetric cryptography, asymmetric cryptography and hash functions.

Symmetric cryptography, also known as secret key cryptography, uses a single key for encryption and decryption, relying on a cryptographic algorithm to create a single key for both the sender and recipient. Secret key cryptography can be used for both in-transit data and at-rest data but is largely reserved for at-rest data. This is due to the simplicity and the nature of this form of encryption, which can become compromised due to the transmission of the secret key. Asymmetric encryption, also known as public key encryption, uses separate keys for the encryption and decryption processes, with one key remaining private and the other being shared for public use. The private key is unable to be derived from the public key while the public key can be discovered through the private key. Private keys should only be known by the message owner.

Hash functions are an irreversible, one-way form of cryptography in which data is protected while the original message becomes irrecoverable. Hashing algorithms create unique outputs for each provided input and can only be cracked by attempting to enter every input possible.Hash functions can also be applied to file hashes and passwords. File hashes are used to validate that a file is from a verified publisher while password can be hashed and stored within a database as a hashed value to secure entry.

How is cryptography used in real life?

Cryptography is used in multiple everyday functions, such as in secure web browsing, ATM withdrawals and more.

Cryptography is put into practice anytime information requires secure transmission from a sender to a recipient. Information is requested constantly in everyday life, so safe transmission is crucial. For instance, any time a credit card transaction is made, whether via an ATM, an online shop, or a physical storefront, data is exchanged between the consumer’s bank, the consumer’s device, third-party payment processors, and the business’s bank to transmit the proper amount of money between locations. It is pivotal that cryptography and encryption techniques are used in this setting to ensure malicious parties cannot intercept and view bank account information to commit catastrophic theft. Additional examples of cryptography in real life include secure web browsing, file storage and the use of a GSM mobile phone.

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