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Akshayaram Srinivasan, Peihan Miao, Prashant Nalini Vasudevan

2019

4

March

Efficient Leakage-Resilient Secret Sharing Page 1 Efficient Leakage-Resilient Secret Sharing Peihan Miao Akshayaram Srinivasan Prashant Nalini Vasudevan UC Berkeley Page 2 Secret Sharing [Shamir’79, Blakley’79] 𝜎 𝑠ℎ1 ,…,𝑠ℎ𝑛 Share Reconstruction: Given at least 𝑡 shares, can reconstruct 𝜎 Secrecy: Given (𝑡 − 1) shares, no information about 𝜎 Several applications: MPC, threshold crypto, leakage-resilient circuit compilers, ... Efficient constructions, eg, Shamir, which has rate = 𝜎 𝑠ℎ 𝑖 = 1 Page 3 Secret Sharing [Shamir’79, Blakley’79] 𝜎 𝑠ℎ1 ,…,𝑠ℎ𝑛 Share What if there are side-channels? What if the adversary, in addition to (𝑡 − 1) full shares, has some information about the others? Reconstruction: Given at least 𝑡 shares, can reconstruct 𝜎 Secrecy: Given (𝑡 − 1) shares, no information about 𝜎 Page 4 Local Leakage Resilient Secret Sharing [GK’18, BDIR’18] 1. Adversary specifies: 2. Adversary is given …