Category: Confusion and diffusion
Modes of operation – Block Ciphers and Their Modes of Operation
14.4 Modes of operation In the previous sections, we have discussed in detail how a block cipher encrypts a single block of plaintext data. But how should we proceed when faced with a large number of blocks? There are several possible answers to this question, each coming with its own advantages and disadvantages. The different…
Read MoreCBC-MAC – Block Ciphers and Their Modes of Operation
14.4.3 CBC-MAC Looking closely at Figure 14.9 again, we can see that the last cipher block c3 depends on all plaintext blocks m1,m2,m3. Of course this is also true for an arbitrary number of plaintext blocks. Therefore, one can construct a message authentication code over some plaintext message m called the CBC-MAC by encrypting m…
Read More