# Unit 2.5 Assignment 1

Decent Essays
2.5 Solution to the security issues • In order to manage the encryption keys securely, enterprises need to employ encryption in their cloud environment, while maintaining secure off-site storage of their encryption keys. • Encryption keys should never be stored in the same place as encrypted data. The keys used for encrypting sensitive customer data should be managed effectively by periodic key rotation and re-encryption of data with new keys. • Employees should be not be given more access than what is needed to complete their tasks. Byzantine failure is very common fault in cloud servers, in which a storage server can fail in arbitrary ways. On occurrence of a byzantine failure system responds in an unpredictable way. At the point when…show more content…
They wish to lock up the documents in a cabinet so that the cabinet can be opened, if and only if, six or more of the scientists are present. What is the smallest number of locks needed? What is the smallest number of keys to the locks each scientist must carry? If five scientists are considered together and there is a specific lock which they cannot open. If we consider a particular scientist, he must have the keys of those locks which cannot be opened by any five scientists from among the other ten scientists. Five scientists among 11 scientists can be selected in 11C5=462 ways, and among ten scientists, five scientists can be selected in 10C5 = 252 ways. So, the minimal solution requires 462 locks and 252 keys per 14 scientists. This is clearly impractical, and if number of scientists increases it can become exponentially worse. 2.7 Secret Sharing Schemes Different secret sharing schemes are discussed below: Simple secret sharing 1. Additive Secret Sharing In additive secret sharing for a given secret S_F,n 1 random integers R =r1, r2...... rn−1 are selected by the dealer uniformly from F. X then computes Sn = S − Σ n−1 i=0 rimodF X sends the share si = ri to each player Pj 1 ≤ j ≤ n − 1 , and the share sn is sent to Pm The secret S reconstruction is trivial and it can be generated simply by adding all the shares together. S = Σn i=0