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Client-Server system and password protection by hashing

Q1 A client/server system requires remote users to use a password to log onto the server. Describe a simple scheme that would thwart eavesdroppers from obtaining and/or spoofing the password.

A1. unknown

Q2 Bob is concerned about the possibility of having his 100k byte file modified without his knowledge, so he calculates a 100 byte hash. Alice, unbeknownst to Bob, changes a single character in Bob's file. Assuming that Bob used a strong hash function, what would the hash value of the modified file look like, as compared with the original hash value?

A2. The hash value of the modified file would look entirely different than the original hash value.

Q3. Invent a simple hash function. Identify its weaknesses.

A3. Unknown

V/R

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Hi,
I am very happy to help you with these questions.

All the best for your future.

Regards,
Leela Krishna

========================= Answer Starts =======================

Q1 A client/server system requires remote users to use a password to log onto the server. Describe a simple scheme that would thwart eavesdroppers from obtaining and/or spoofing the password.

A1. The simple scheme to thwart eavesdroppers is to ENCRYPT the password before transmission and decrypt the password on the server side.

Q2 Bob is concerned about the possibility of having his 100k byte file modified without his knowledge, so he calculates a 100 byte hash. Alice, unbeknownst to Bob, changes a single character in Bob's file. Assuming that Bob used a strong hash function, what would the hash value of the modified file look like, as compared with the original hash value?

A2. The hash value of the modified file would look entirely different than the original hash value.
(My comment: Your answer is correct. The hash value would be different from the original hash value as Bob has used a strong

hash algorithm)

Q3. Invent a simple hash function. Identify ...

Solution Summary

Solution clearly explains about client-server systems and also explains the ways of thwarting eavesdroppers by using hash functions

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