What is the function of a cipher in cybersecurity?

The function of a cipher in cybersecurity is to perform encryption of data. Ciphers are algorithms used to transform plaintext data into an unreadable format known as ciphertext. This transformation is crucial for protecting sensitive information, as it ensures that even if data is intercepted or accessed unlawfully, it remains unintelligible without the correct decryption key. Encryption using ciphers helps maintain confidentiality, a key principle of cybersecurity, by safeguarding data from unauthorized access and ensuring secure communication channels. This process is fundamental when handling data such as passwords, personal information, or financial transactions, where security and privacy are paramount.