A method comprising obtaining a Bloom filter array, wherein a size of a first Bloom filter is smaller than a size of a second Bloom filter and modifying at least a portion of the plurality of Bloom filters to create a modified Bloom filter array comprising a modified plurality of Bloom filters each of which having a same size, wherein the same size is greater than the size of the first Bloom filter, wherein said modifying comprises: duplicating the first Bloom filter to create a modified first Bloom filter comprising two or more concatenated copies of the first Bloom filter. The method may also include performing lookup in the Bloom filter array by computing a hash value of a key and accessing a bit in the hash value location in each Bloom filter of the modified Bloom filter array to determine lookup outcome in each Bloom filter.