Optimal Functional 2^s-1-Batch Codes: Exploring New Sufficient Conditions

THIS PAPER IS ELIGIBLE FOR THE STUDENT PAPER AWARD. A functional k-batch code of dimension s consists of n servers storing linear combinations of s linearly independent information bits. These codes are designed to recover any multiset of k requests, each being a linear combination of the information bits, by k disjoint subsets of servers. A recent conjecture suggests that for any set of k=2^s-1 requests, the optimal solution requires 2^s-1 servers. This paper shows that the problem of functional k-batch codes is equivalent to several other problems. Using these equivalences, sufficient conditions are derived that improve the understanding of the problem and enhance the ability to find the optimal solution.