{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

L02_HashMDMAC

# For any given pair of people the possibly of them

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ntire year. For any given pair of people, the possibly of them having the same birthday is 1/m = 1/365 ; them Probability of zero collision Probability = Probability that all of the n people have different birthdays = m * (m-1) * (m-2) *…* (m-n+1) / mn (m-1) = 1 – n(n-1)/2m approximately when m>>n n(n-1)/2m Pcollision = 1 – Probability of zero collision = n(n-1)/2m approximately n(n-1)/2m How difficult to find a Hash collision ? How secure is a one-way hash with 64-bit output ? Based on the property of a good hash function, the hash Based output of any input string should be uniformly distributed over the hash output space of size m=264 the This is analogous to the fact that the birthday of any given This person is uniformly distributed over any days within a year (i.e. output space of size m = 365) Thus, according to the Birthday Paradox, if no. of all possible Thus, outcomes = m, we only need to try about n = √ m inputs to we the hash function to have a good chance to f...
View Full Document

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern