Exercise 3 RSA We consider the use of RSA with p 5 and q = 7 a) Compute n, Phi(n) b) We choose e = 11, determine d c) Which information do you share as the public key? Which information is kept as the private key? Separately encrypt each value from 0 to 34 (character encodings of "M") using the public key Separately decrypt each value from 0 to 34 (character encodings of "C") using the private key Encrypt the plaintext = "information assurance" using the public key from above. Determine the cyphertext. d) e) Exercise 4 Classify the following functions according to the definitions for code, encryption, checksum, hash and cryptographic hash functions from the document "3 BasicTerms.pdf" and explain why the function meets the requirement of each definition or how it does not meet the requirements a) Memory address -> Parity bit of memory address b) Memory address -> Line address in a Cache c) Last Name -> Last 4 digits of a credit card d) F(US telephone number) = SSN of primary account holder e) Encryption function Fr(m) = E(M,K) with a fixed choice of a public key k f) Modular exponentiation: gm mod p with generator g and large prime number p Exercise 5 a) Assume that a password (using ASCII encoding) has the following SHA2 message digest 1C8BFE8F801D79745C4631D09FFF36C82AA37FC4CCE4FC946683D7B336B63032 Find the password for this SHA2 value (hint: use the 2017 list of common passwords https://en.wikipedia.org/wiki/List of themost_common_passwords) b) Determine the ten 256bit SHA2 values for the password ICS455" when choosing the digits 10,1,2,...,9) as salt SHA-1 hash, e.g. Windows 8.1 as listed at Discuss the issues regarding the integrity of such a download considering the weakness c) Consider the situation where you download a software package that is provided with a https://support.microsoft.com/en-us/help/3123479 of SHA-1 (same weakness as for MD5) as mentioned in unixwiz.net/techtips/iquide-crvpto-hashes.html d) Explain the additional issues for such a download when a hash function were used instead of SHA-1 that has a weakness regarding pre-image resistance or when one is used that has a weakness regarding second pre-image resistance Exercise 3 RSA We consider the use of RSA with p 5 and q = 7 a) Compute n, Phi(n) b) We choose e = 11, determine d c) Which information do you share as the public key? Which information is kept as the private key? Separately encrypt each value from 0 to 34 (character encodings of "M") using the public key Separately decrypt each value from 0 to 34 (character encodings of "C") using the private key Encrypt the plaintext = "information assurance" using the public key from above. Determine the cyphertext. d) e) Exercise 4 Classify the following functions according to the definitions for code, encryption, checksum, hash and cryptographic hash functions from the document "3 BasicTerms.pdf" and explain why the function meets the requirement of each definition or how it does not meet the requirements a) Memory address -> Parity bit of memory address b) Memory address -> Line address in a Cache c) Last Name -> Last 4 digits of a credit card d) F(US telephone number) = SSN of primary account holder e) Encryption function Fr(m) = E(M,K) with a fixed choice of a public key k f) Modular exponentiation: gm mod p with generator g and large prime number p Exercise 5 a) Assume that a password (using ASCII encoding) has the following SHA2 message digest 1C8BFE8F801D79745C4631D09FFF36C82AA37FC4CCE4FC946683D7B336B63032 Find the password for this SHA2 value (hint: use the 2017 list of common passwords https://en.wikipedia.org/wiki/List of themost_common_passwords) b) Determine the ten 256bit SHA2 values for the password ICS455" when choosing the digits 10,1,2,...,9) as salt SHA-1 hash, e.g. Windows 8.1 as listed at Discuss the issues regarding the integrity of such a download considering the weakness c) Consider the situation where you download a software package that is provided with a https://support.microsoft.com/en-us/help/3123479 of SHA-1 (same weakness as for MD5) as mentioned in unixwiz.net/techtips/iquide-crvpto-hashes.html d) Explain the additional issues for such a download when a hash function were used instead of SHA-1 that has a weakness regarding pre-image resistance or when one is used that has a weakness regarding second pre-image resistance
