Symmetric and Asymmetric encryption – what’s the difference?

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Introduction

Encryption has been used for thousands of years by governments and the military. Now that the internet has become so central to so many people’s lives, it is important that we secure our communications, and there are many ways to do this. In this essay, I will explore the differences between Symmetric and Asymmetric encryption.

Symmetric Encryption

About

Encryption is defined as symmetric if the cipher text can be decrypted by knowing the encryption algorithm and the encryption key. In other words, symmetric encryption uses a single key to both encrypt and decrypt the required message to be sent.  Symmetric-key requires that you know which computers will be talking to each other so you can install the key on each one.

Advantages

Some advantages of symmetric include:

  • It is simple: This type of encryption is easy to carry out. All you have to do is create and share the secret key and then you can start to encrypt and decrypt messages
  • It is faster and uses less computer resources than asymmetric encryption
  • A different key is used for each client, so if one key is cracked then not everyone’s is.

Disadvantages

  • Messages or files encrypted with symmetric encryption can be decrypted if the language that the text is written in is known and the relative frequencies of the text are analysed.
  • You can’t let people encrypt their information without allowing them to decrypt everyone’s the information as well.

Asymmetric Encryption

About

With asymmetric encryption you can create a public and private key pair. Then you can add your public key along with your email address to a server. Then anyone who wants to send you an encrypted email can use a plugin to automatically get the public key and encrypt the message. If you also have a plugin for your email client then it automatically decrypt the message using your private key.

Advantages

Some advantages of symmetric include:

  • Encryption keys (public) can be distributed publicly without concern of a security breach
  • Allows user authentication with digital signatures. Any tampering with a file is detected as you cannot modify an asymmetrically encrypted file without altering the signature.

Disadvantages

  • More complicated, as public keys need to be checked and there are two separate keys, rather than one
  • If someone finds the private key they can access all of the different files that have been encrypted.
  • If the private key is lost, you’re stuffed forever

Author

Phil Tower

Email: phil@philtower.co.uk -- Website: philtower.co.uk -- Bio: Young IT Consultant looking for opportunities

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