Encryption
Computer Science: Cambridge International GCSE, topic 1.2.6
Encryption
If sensitive data is going to be transferred, then it is important that we keep it secure from third parties.
Encryption
- Encrypting data is the process of scrambling data according to a specific algorithm so that it cannot be read by third parties.
- Only the intended recipient will know how to decode the data.
Keys
- A lot of encryption depends upon secret keys, which are shared secret pieces of data.
- Keys are made up of a pair of very large prime numbers, either 256 or 1,024 bits long.
- It would take an impractical amount of time to guess the key. So we say that the encryption is secure.
Wireless communication
- It is especially important to encrypt wireless communication.
- Protocols exist for wireless communication, such as WiFi Protected Access version 2 (WPA2), which encrypt all traffic.
Symmetric Encryption
The use of encryption is vital to protect our private information. One type of encryption is symmetric encryption.
Symmetric encryption
- Symmetric or private key encryption is used to encrypt data for transmission.
- A private key is used to convert plain text into cypher text.
- This cypher text and private key are then transferred to another location or person.
- The key is then used to decrypt the cypher back into plain text.
Security
- Using a single key to encrypt and decrypt text proposes a massive flaw in security, as anyone with the key can decrypt the cypher.
- As with passwords, the longer the encryption key, the less likely it is to be compromised by brute force, and so the more secure the encryption.
Test yourself on Encryption
A lot of encryption depends upon secret keys - what is a secret key?
Which of the following is a well-known wireless communication encryption protocol?
Symmetric Encryption
Is the following statement true or false?
Anyone with the private key can decrypt the cypher text generated by symmetric encryption.