CIPHER or cipher is a mathematical formula that depends on the key and is used to ensure the secrecy of the transmitted information. Using a cipher, you can convert text into an encoded message that can only be decrypted using a suitable key.
Ciphers are used to ensure the security of confidential information and protect it from unauthorized access. One of the earliest examples was the Caesar cipher, in which the letters of the alphabet were shifted by a certain number of places to create an encoded message. Modern ciphers are much more complex and include algorithms and mathematical equations for encrypting and decrypting data.
There are two main types of ciphers:
- symmetric ones use the same key for encryption and decryption;
- The asymmetric ones use two different keys, one for encryption and the other for decryption.
Symmetric ciphers are faster and easier to use, but they may be less secure because if the key is discovered, the encrypted data can be easily decrypted. Asymmetric ciphers are safer because two different keys make it much more difficult for unauthorized access to data.
Ciphers play an important role in computer security, especially in the field of cryptography. They are used to protect sensitive data such as financial transactions, medical records and personal data. They are also used to protect communications over the Internet, including email, instant messaging, and online banking.