Public key encryption is a cryptography method that leverages two different keys, known as public keys , and private keys. We live in a world where wireless protection is of utmost importance because confidential data and sensitive information are uploaded to the internet. As the number of info uploaded online rises, so does the financial expense to prevent cybercrime. Cyber-attacks are incredibly hazardous, and robust safety steps are necessary more than ever. Companies must safeguard their information by securing their digital properties, like server access, verification mechanisms, and protect interaction protocols (SSL/TLS).
Even today, some businesses that verify their client identity with passwords send the information via plain text, which is as simple to read as any plain document. Such companies can easily fall victim to all sorts of cyberattacks, like vishing, smishing, email phishing, man-in-the-middle attacks, and many more. Private information transmitted and kept in transparent form can easily be breached in such unsafe environments.
The public key encryption method is essential for securing data transmission between the two communicating parties using public and private keys. The SSL certificates that are known for protecting websites and users from being attacked by malicious actors use the same public key encryption technology to make it possible. Here we will start with what is public-key encryption and then will explain its working and strengths.
What is public-key encryption?
Public Key Encryption, also known as public-key cryptography, uses a pair of keys to encode and decode the data. One key is the public key that is offered to all the clients. Another key is the private key, which is only used by the server. The browser encodes the data with the public key decoded by the server by using the private key. The server then sends back the reply in encrypted form using the private key decrypted by the user with the public key’s help. Public key encryption is widely used in SSL or TLS security protocol to protect the data from the attackers’ reach.
What is a cryptographic key?
In cryptography, a key is a bit of data used to scramble info such that it looks vague; it is either a huge number or a series of alphanumeric characters. When encryption is applied to the plain text, it comes out as ambiguous so that it cannot be read without using the appropriate key for decryption.
Assume that we want to encrypt the word “hi” by using this key “23kfakv88o”. Our plaintext “hi” is encoded and appears as “COsad63HJ=”, which looks like random data and cannot be read. By using the appropriate decryption key, we can get the plain text back in its original form.
How does public-key encryption work?
In the public key encryption method, two different keys are used to cipher and decipher the information. A public key is offered to the user so that other people can use it to secure communications they wish to send to the holder of the public key. As long as you keep your secret key secure, you can allow anyone to access your public key without sacrificing the privacy of your website.
As everyone can access the key, they can send their encoded messages to the key owner. To ensure that intruders cannot acquire the secret key from the public key, all public-key cryptographic algorithms are based on complicated mathematical equations with highly complex algorithms running the show.
Consider this example to understand the working of public-key encryption clearly:
Alice and Bob want to share their confidential data securely with one another. Let’s say Bob is the proprietor of the secret key. She uses the public key to send cipher text data to him. Bob utilizes its private key to decode the info received from Alice. He then forwards his encoded reply to Alice with the help of the secret key. Alice again uses the public key to decipher the information coming from Bob.
Strength of Asymmetric Keys
Here are some of the key strengths of using asymmetric keys:
- In public-key cryptography, it is not required to share keys, thus removing the main key communication issue.
- The main benefit of public-key cryptography is improved protection: private keys do not need to be passed on or disclosed to others.
- Electronic certificates are encouraged so that the receiver can check that the information is coming from a specific recipient.
- Includes nonrepudiation so that the sender cannot refuse their role in data communication.
Is Public Key Encryption Better?
Symmetric keys or private key encryption uses only one key to cipher and decipher the information. There is always a considerable risk of security leakage. Since public key encryption utilizes two keys to encode and decode the information, it is challenging for hackers to access and read the info shared between two parties.
Symmetric keys are although faster than asymmetric keys, but the latter provides higher security and cannot be easily attacked. So, public-key encryption is better than private key encryption.
How does TLS/SSL Deliver Confidentiality?
Transport Layer Security (TLS) or Secure Socket Layers (SSL) uses public-key cryptography techniques to securely transmit the information from a browser to a server and vice versa. The SSL/TLS certificates hold the user’s public key to send encrypted messages to the server. The secret key is kept hidden by the web server to encode and decode the data.