From the course: Learning Cryptography and Network Security

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Understand modes of operation

Understand modes of operation

From the course: Learning Cryptography and Network Security

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Understand modes of operation

- [Instructor] When using a stream cipher there are different chaining modes. In this segment, we'll review the various modes of operation when generating a stream cipher. A chaining mode defines the way that the plain text, the key, and the cipher text generate the stream of cipher text that is transmitted to the recipient. Electronic Codebook is the simplest mode in that there is no feedback. Each 64-bit block is encoded independently, but it uses the same key, which means that the same plain text will always result in the same cipher text. The next few modes will add randomness and feedback to the messages to provide additional security. Cipher Block Chaining takes a block of plain text and does an exclusive or operation with the previous block before it is encrypted. Because each cipher text block depends on all plain text blocks to be processed up to that point, we need what is called an initialization vector. An…

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