Practical Suitability and Experimental Assessment of Tree ORAMs

Table 2

Notations used for Ring ORAM.

N	The total number of leaves
L	The height of the tree
Z	The number of real blocks in each bucket
S	The number of dummy blocks in each bucket
Path(x)	The path from leaf node x to the root
Path(x, i)	The bucket at level i on path x
GetPath(x,a)	Read the path x looking for block with address a
St	The client’s local stash
PMap	The position map stored on the client
x≔PMap[a]	Block a is assigned to leaf node x
EvPath()	Evict path
ShuffPath(x)	Shuffle the buckets on path x
offs	The offset of a block stored in a bucket
block[offs]	The block stored in the bucket at offset offs
RBuck(i)	Read a complete bucket i
WBuck(i, y)	Write bucket i with the contents from y
URand	Uniform Random distribution
GetBOffs(Path(x,i),a)	Gets the block offset of the block with address a on path x on level i.