Which of the following is true about stream ciphers?

Stream ciphers are designed to encrypt plaintext data one bit or one byte at a time, which allows for the processing of data in a continuous flow. This characteristic makes them particularly suitable for applications where data is transmitted in a real-time manner, such as in voice over IP or video streaming. By encrypting data at a granular level, stream ciphers can provide immediate encryption and decryption, which lends itself to high-speed operations.

In contrast to block ciphers, which encrypt data in fixed-size blocks (such as 64 or 128 bits), stream ciphers handle smaller chunks of data, making them more adaptable to certain scenarios where the input size is variable or continuous. This bit-at-a-time approach does not imply reduced security by itself; rather, the security of both stream and block ciphers largely depends on their underlying algorithms and how they are implemented.

Stream ciphers are often faster than block ciphers, especially for certain types of applications. While there may be contexts where block ciphers are preferred for their structure and security frameworks, stream ciphers are utilized effectively in environments requiring speed and efficiency.