Consider a mac technique called cbcmac

Assignment Help Computer Network Security

Reference no: EM13168144

Informally speaking, a MAC is secure if no efficient forger can generate any valid (message, tag) pair, even if the forger is given a tagging oracle. (As we discussed in class a tagging oracle is an algorithm that will tag arbitrary messages for an attacker.)

Consider a MAC technique called CBCMAC. The algorithm takes a message, m, a secret key, k, and runs CBC mode encryption on the blocks of the message. For purposes of this problem the initialization vector will always be zero. The tag is the final block of the ciphertext.

Demonstrate that this MAC scheme is not secure for variable length messages. Write pseudocode for an algorithm, F, that, given a tagging oracle Tk(m), can easily generate a (message, tag) pair for a message that was not sent to the tagging oracle.

Reference no: EM13168144

Questions Cloud

You can push multiple operands on the stack : You can push multiple operands on the stack. The operation will always use the two topmost values. For example, to evaluate (A+B+C), you can use the code below:

Pattern matching : Question 1 In sed, when you do pattern matching, the largest pattern is always matched first, left to right.

Consider architecture a that has the addressing : Consider architecture A that has the addressing modes below for the ADD instruction. Based on the ADD instruction, is this architecture better be encoded as a fixed-length instruction or a variablelength

Convert from base 10 to base 2. : Convert from base 10 to base 2.

Consider a mac technique called cbcmac : Consider a MAC technique called CBCMAC. The algorithm takes a message, m, a secret key, k, and runs CBC mode encryption on the blocks of the message. For purposes of this problem the initialization vector will always be zero. The tag is the final..

Create an array that stores in integers from the keyboard : create an array that stores in integers from the keyboard and then I can scan that array to check numbers in order, if the number I check is greater than the previous then I will set the next number in the array to the higher value.

Write a generic class : Write a generic class (using Java generics) called Pair that stores two values of the generic type. It should have a constructor to set them, two methods getfirst() and getsecond() to retrieve them.

Definition of two queues : Write a code in C lenguage for the definition of two queues, one to hold the process in ready state and one to hold the process in waiting state. The queue should be designed to manage a process structure. Please comment the code.

User Account

All Pages