Common use of Setup and corruption Clause in Contracts

Setup and corruption. In the first phase, the challenger generates the public parameters and the signature keys for the parties. Given the public information, can adaptively corrupt parties, learn their secret information, and potentially change their public keys. (1) Compute pp ← Setup(1κ, 1n). (2) For every i ∈ [n], compute (vki, ski) ← KeyGen(pp). (3) Invoke A on (1κ, 1n, pp, {vk1, . . . , vkn}) and initialize I = ∅. (4) As long as |I| ≤ t and A requests to corrupt a party Pi: (a) Send ski to A and receive back vk′ . (b) If mode = bb-pki, set vki = vk′ . (c) Set I = I ∪ {i}.

Setup and corruption. In the first first phase, the challenger generates the public parameters and the signature keys for the parties. Given the public information, can adaptively corrupt parties, learn their secret information, and potentially change their public keys. (1) Compute pp ← Setup(1κ, 1n). (2) For every i ∈ [n], compute (vki, ski) ← KeyGen(pp). (3) Invoke A on (1κ, 1n, pp, {vk1, . . . , vkn}) and initialize I = ∅. (4) As long as |I| ≤ t and A requests to corrupt a party Pi: (a) Send ski to A and receive back vk′ vkri. (b) If mode = bb-pki, set vki = vk′ vkri. (c) Set I = I ∪ {i}.

Setup and corruption. In the first first phase, the challenger generates the public parameters and the signature keys for the parties. Given the public information, can adaptively corrupt parties, learn their secret information, and potentially change their public keys. (1) Compute pp ← Setup(1κ, 1n). (2) For every i ∈ [n], compute (vki, ski) ← KeyGen(pp). (3) Invoke A on (1κ, 1n, pp, {vk1, . . . , vkn}) and initialize I set 𝓧 = ∅. (4) As long as |I| |𝓧| ≤ t and A requests to corrupt a party Pi: (a) Send ski to A and receive back vk′ vk'i. (b) If mode = bbb-pki, set vki = vk′ vk'i. (c) Set I 𝓧 = I 𝓧 ∪ {i}.