Cryptographic hash functions, Computer Network Security

Assignment Help:

(a)

(i) Bob has public RSA key (n = 77, e = 7).

Show that Bob's private key is (d = 43).

(ii) Alice wants to send the message m = 13 to Bob. She encrypts the message using Bob's public key. What is the value of the ciphertext that Alice sends to Bob?

(iii) David has also sent an encrypted message to Bob. The ciphertext value that Bob receives from David is 17. Showing all your working, use Bob's key to decrypt this ciphertext and recover the value of David's message.

(b)

Consider cryptographic hash functions.

(i) What is meant by collision resistance for a hash function?

(ii) What common usage do hash functions have in connection with digital signatures?

(iii) What is the difference between a hash function and a message authentication code (MAC)?

(iv) Why is it recommended to use a hash function with 2n bits of output when it is used as component in a system designed for n bits of security?


Related Discussions:- Cryptographic hash functions

Ip datagram format, IP DATAGRAM SIZE:  Datagrams may have different si...

IP DATAGRAM SIZE:  Datagrams may have different sizes i.e. Header area is generally fixed (20 octets) but can have various options. Data area may contain between 1 octet and 6

Digital signatures, Digital Signatures Digital Signatures are encrypted ...

Digital Signatures Digital Signatures are encrypted messages which can be proven mathematically to be authentic. These are created in response to rising requirement to verify in

Programming, SDES encryption and decryption

SDES encryption and decryption

Plaintext, how to encryt the data in plaintext cipher

how to encryt the data in plaintext cipher

Define shift operation, SHIFT OPERATION:  This operation replaced all...

SHIFT OPERATION:  This operation replaced all bits to the left one position. For example in the diagram below a 16-bit CRC hardware is given, which needs three Exclusive OR (

Nstissc security model, NSTISSC SECURITY MODEL The NSTISSC Security Model ...

NSTISSC SECURITY MODEL The NSTISSC Security Model provides a detailed perspective on security. While the NSTISSC model covers the 3 dimensions of information security, it removes

Information and network security, Information and Network Security Part ...

Information and Network Security Part 1- Recovery of an encrypted `word' using a forward search attack. Complete and correct summary for part 1. Adequately commented, clea

Derive the transmitted crc header checksum, QUESTION (a) Consider the f...

QUESTION (a) Consider the following digital bit stream 01001100 is to be encoded in: i. NRZ-I ii. Pseudoternary iii. Manchester iv. Differential Manchester Show th

Websphere administrator, Websphere Administrator: Working as Webspher...

Websphere Administrator: Working as Websphere Administrator in the department called DART (Database Architecture Re-Engineering and Tuning). The major responsibilities are t

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd