Abstract: A method of providing a search index based on a Bloom filter in a distributed data sharing environment based a block chain includes generating, by a data generating device, Bloom filters used as the search index on the basis of a hash value calculated by applying a hash function to a keyword set for searching for data which is to be shared, generating, by a block providing server, a new block on the basis of the Bloom filters and the data received from the data generating device and performing proof of work (PoW) on the new block, for adding the new block to the block chain, and distributing, by a block distributing server, block chain data including the new block added to the block chain.

Abstract: Embodiments are described for ordering records. Aspects include blocking one or more records and storing the one or more blocked records as a set of records. Aspects also include reserving space for a metadata record for each of the one or more blocked records that meet one or more selection criteria and generating the metadata record for each of the one or more blocked records that meet the one or more selection criteria. Aspects further include adding the metadata records to the set of blocked records and storing the set of records including the metadata records.