What Does Encryption Mean?

Encryption is the process of using an algorithm to transform plain text into cypher text in order to ensure that sensitive data remains unreadable to unauthorized users.


Encrypted data usually looks like a long sequence of random letters and numbers. Once data is encrypted, it can only be turned back into plain text and made readable again by using the correct encryption key.

Encryption is essential for ensuring the trusted delivery and storage of sensitive information. Stream ciphers, which are used mostly for real-time communications, encrypt data one bit or byte at a time. Block ciphers break data into larger segments, typically about 64 bits, before encrypting it.

Techopedia Explains Encryption

Often the most difficult problems in encryption is key management, which includes the generation, use, archiving and deletion of symmetric and asymmetric encryption keys.

How Symmetric Encryption Works

Symmetric encryption ciphers use the same key to encrypt and decrypt a message and are often simply passwords. This type of encryption is fast, efficient and well-suited for encrypting documents. It is not often used for highly sensitive communications, however, because both parties are required to have access to the same secret key.

A well-known symmetric encryption algorithm is the Data Encryption Standard (DES), which uses a 56-bit key and is not considered attack-proof. The Advanced Encryption Standard (AES) is considered more reliable because it uses a 128-bit, a 192-bit or a 256-bit key.

How Asymmetric Encryption Works

Asymmetric encryption (also called public key cryptography) works by generating pairs of mathematically related keys. One key is used to encrypt a message and the other key is used to decrypt the message. The sender encrypts a message using the receiver’s publicly available key. The message is then decrypted with the receiver’s private key.

Asymmetric encryption is often compared to a locked mailbox that has a slot to receive messages. Anyone who knows the address of the mailbox (the public key) can send a message, but only the owner of the mailbox has the private key to open the mailbox and read the message.

How Homomorphic Encryption Works

Homomorphic encryption is an encryption technique that is supported by special type of algorithm that allows certain types of operations to be carried out on the ciphertext without requiring access to a secret key.

Homomorphic encryption is important because it allows users to perform computations on encrypted data without first having to decrypt it.


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Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…