We consider a key agreement setting where two parties observe correlated random sources, and want to agree on a secret key via public discussions. In order to allow the key length to adapt to the realizations of the random sources, we allow the key to be of variable length, subject to a novel variable-length version of the uniformity constraint based on random stopping time. We propose simple, computationally efficient key agreement schemes under the new constraint. The proposed scheme can be considered as the key agreement analogue of variable-length source coding via Huffman coding, and the Knuth-Yao random number generator.

翻译：本文考虑一种密钥协商场景：通信双方观测到相关随机信源，并希望通过公开讨论协商出一个共享密钥。为使密钥长度能自适应随机信源的具体实现，我们允许密钥具有可变长度，并基于随机停时提出了一种新的变长均匀性约束条件。在该新约束下，我们设计了一种简单且计算高效的密钥协商方案。该方案可视为哈夫曼编码与Knuth-Yao随机数生成器在变长信源编码领域的密钥协商类比。