What Is Network Encryption?

Encryption technology makes your devices safer

When we go online at home or in a business setting, we rely on network encryption to safeguard our data and transactions. Here's a look at what exactly network encryption is and how it protects our digital information.

Network encryption is also sometimes called network layer encryption or network-level encryption.

Network encryption concept illustration with a lock and digital data
Andriy Onufriyenko / Getty Images

What Is Network Encryption?

When we go online to bank or shop, our transactions must be protected. Encryption is a popular and effective network security process designed to keep our information safe.

Encryption effectively hides data and message contents from prying eyes. This information can be retrieved only through a corresponding decryption process. Encryption and decryption are common techniques in cryptography, the scientific discipline behind secure communications.

There are various encryption and decryption processes (also called algorithms), but most encryption algorithms achieve a high level of data protection by using keys.

What Is an Encryption Key?

In computer cryptography, a key is a long sequence of bits used by encryption and decryption algorithms. For example, the following represents a hypothetical 40-bit key:

00001010 01101001 10011110 00011100 01010101

An encryption algorithm takes the original, unencrypted message and a key and then alters the original message mathematically based on the key's bits to create a new encrypted message. A decryption algorithm takes an encrypted message and restores it to its original form using one or more keys.

Some cryptographic algorithms use a single key for both encryption and decryption. This kind of key must be kept secret, or else anyone with knowledge of the key used to send a message could supply that key to the decryption algorithm to read the message.

Other algorithms use one key for encryption and a second, different key for decryption. The encryption key can remain public in this case, because if the decryption key is unknown, no one can read the message. Popular internet security protocols use this so-called "public-key" encryption.

Public key encryption is sometimes called "asymmetric encryption."

Encryption on the Internet

Modern web browsers use the Secure Sockets Layer (SSL) protocol for secure online transactions. SSL works by using a public key for encryption and a different, private key for decryption. When you see an HTTPS prefix on the URL string in your browser, it means that SSL encryption is happening behind the scenes.

Encryption on Home Networks

Wi-Fi home networks support several security protocols, including WPA and WPA2. While these aren't the strongest encryption algorithms, they're sufficient enough to protect home networks from outside snoops.

To determine what kind of encryption your home network uses, check your broadband router (or another network gateway) configuration.

The Role of Key Length and Network Security

Because WPA/WPA2 and SSL encryption depend so heavily on keys, one common measure of network encryption's effectiveness is its "key length," which means the number of bits in the key.

Early SSL implementations in the Netscape and Internet Explorer web browsers used a 40-bit SSL encryption standard. The initial implementation of ​WEP for home networks used 40-bit encryption keys, as well.

Unfortunately, 40-bit encryption became too easy to decipher by cybercriminals who could guess the correct decoding key. A common cryptography deciphering technique called brute-force decryption uses computer processing to exhaustively calculate and try every possible key one by one.

Security software makers realized that 40-bit encryption was much too lax, so they moved to 128-bit and higher encryption levels many years ago.

Compared to 40-bit encryption, 128-bit encryption offers 88 additional bits of key length. This translates to a whopping 309,485,009,821,345,068,724,781,056 additional combinations required for a brute-force crack.

While there's some processing overhead on devices when they have to encrypt and decrypt message traffic with these keys, the benefits far outweigh the cost.