This lecture covers how to securely share secrets among a group, the mathematical properties of safe primes, the mechanics and vulnerabilities of hash functions, RSA digital signatures, and the basics of polynomial commitments.
As an exercise:
try simulating a small-scale Shamir Secret Sharing scheme. Pick a small prime (e.g., ), a secret , and a threshold . Create a random polynomial of degree 2 (), evaluate it for three "users" (), and then manually use Lagrange interpolation to reconstruct the polynomial and recover the secret S.
References and Links:
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Review how the Birthday Paradox drastically reduces the security of hash functions: math.stackexchange.com/questions/35791/birthday-paradox-expected-number-of-people
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Review the corresponding chapters on RSA and Hash Functions in the course book here: Google Drive Link