本文提出了一种基于ElGamal公钥算法和(t,n)门限的密钥恢复方案。它将要托管的密钥K分成n份并交给n个托管代理保管,当需要恢复时,任何t个代理托管的子密钥均可以恢复密钥K,而任何少于t个代理托管的子密钥均无法恢复。在密钥和子密钥的传送过程中,采用了ElGam al算法和ECC算法作校验,分两个阶段实现,提高了安全性和灵活性。 This paper proposes a key recovery scheme based on ElGamal public key algorithm and (t, n) threshold. It divides the key K to be managed into n shares and hands it over to n managed agents, and any t-agent-managed sub-key can recover the key K when it needs to be restored, while any child less than t agents None of the keys can be recovered. In the key and sub-key transfer process, using ElGam al algorithm and ECC algorithm for verification, implemented in two phases, improving security and flexibility.