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secret sharing schemes
- 1. Secret Sharing Schemes major project
- 2. 1 2 Dead Information Outline or Theft Alive 3 4 secret sharing schemes Secret What to do? Sharing what, when why secret sharing 5 6 schemes Phases Applications
- 3. Information Theft ~Secret and confidential information theft is a major computer crime. ~In 2002, more than $70 million loss was reported due to information theft in US only.
- 4. Dead or Alive ~Somecriminals’ tools (like viruses) tend to destroy information. ~ More than 80% of organizations reported virus’s attacks.
- 5. What to do? ~Havingonly one copy of this information means that if this copy is destroyed there is no way to retrieve it. What to do?? Replicate!!! ~ Replicating the important information will give more chance to intruders to gain access to it. ~ Thus, there is a grate need to keep informat ion in a secure and reliable way. What to do?? Secret Sharing
- 6. Secret Sharing ~The basicidea of secret sharing is to divide information into several pieces such that certain subsets of these pieces (shares) can be used to recover the information. ~ Intruders wants to •GET the info. several shares need to be theft •Destroy. several shares need to be destroyed
- 7. (t, n)- • in a secret sharing scheme there is one dealer and n players. threshold • The dealer gives each player a scheme share in such a way that any group of t (for threshold) or more players can together reconstruct the secret but no group of fewer than t players can. • Such a system is called a (t, n)- threshold scheme
- 8. PROPOSED SECRET SHARINGSCHEME •We assume that the set of participants is P = {P1 , P2 , ... , Pn} •the access structure is Г ={Г1, Г2,… Гm } •S is a secret integer of arbitrary precision, p is a prime number larger than S , and all arithmetic operations are performed mod p. •Assume that there are “t” shareholders in the access instance Гj Є Г. That is if all “t” qualified participants in Гj release shares honestly then the secret can be reconstructed •Also assume the presence of a trusted party (dealer) or a piece of trusted software that can construct and reconstruct the secret
- 9. Secret Sharing Phases ~Shares building phase. ~ Shares distribution phase. ~Secret reconstruction phase. ~Shares update phase.
- 10. phase building distribution reconstructionupdate The Number Qualified The Secret of Shareholders subsets Qs S Set SH of SH S SH Qs Shares Builder S1 S|SH|
- 11. phase building distribution reconstructionupdate Share Holder Share Holder 1 Share Holder 8 S1 2 S8 S2 Share Share Shares Holder Holder S7 0 Builder S3 7 3 S6 S4 Share S5 Share Holder Holder Share 6 Holder 4 5
- 12. phase building distribution reconstructionupdate Share Holder Share Holder 1 Share Holder 8 2 S8 S2 Share Secret Share Holder 0 Builder S3 Holder 7 3 S6 Share S5 Share Holder Holder Share 6 Holder 4 5
- 13. phase building distribution reconstructionupdate Share Holder Share Holder 1 Share Holder 8 2 Share Share Holder Holder 7 3 Share Share Holder Holder Share 6 Holder 4 5
- 14. Applications secure implementation of an encrypted backup system encrypted Assuming that data recoveries are needed rarely, backup backup data can be public key encrypted -- this can be done system automatically and without user interaction -- while the private recovery key is protected via secret sharing. The director of a bank generates shares for the bank's shares for the vault unlocking code and hands them out to his bank's vault employees. unlocking Even if the director is not available, the vault can be code opened, but only, when a certain number of employees do it together. Good passwords are hard to memorize. A clever user could use a secret sharing scheme to generate a set of Sharing shares for a given password and store one share in his password address book, one in his bank deposit safe, leave one share with a friend, etc. If one day he forgets his password, he can reconstruct it easily.
- 15. Thank You Made By : Sandeep Kumar Anuj Singh Navdeep Garg