Title :
A novel unbalanced tree structure for low-cost authentication of streaming content on mobile and sensor devices
Author :
Kandappu, Thivya ; Sivaraman, Vijay ; Boreli, Roksana
Author_Institution :
Sch. of Electr. Eng. & Telecommun., UNSW, Sydney, NSW, Australia
Abstract :
We consider stored content being streamed to a resource-poor device (such as a sensor node or a mobile phone), and address the issue of authenticating such content in realtime at the receiver. Per-packet digital signatures incur high computational cost, while per-block signatures impose high delays. A Merkle hash tree combines the benefits of the two by having a single signature per-block (at the root of the tree), while allowing immediate per-packet verification by following a hash-path logarithmic in the number of packets. In this paper we explore how the structure of the Merkle tree can be adapted to improve playback performance for streaming content. We make three specific contributions: First, we develop a new unbalanced authentication tree structure called the α-leaf tree that is a generalisation of the Merkle tree. We derive several key properties of this tree, highlighting the impact of the imbalance parameter α. Second, we present a theoretical model to quantify the benefits of our unbalanced tree structure in reducing startup delays for streaming applications by optimally readjusting the burden of authentication across packets. Third, we validate via simulation the suitability of our scheme to two representative applications, namely audio streaming to a low-cost sensor device and video streaming to a mobile phone, and demonstrate that startup delays can be reduced without affecting stall rates. We believe our authentication tree structure is of importance both theoretically, as a generalisation of the Merkle hash tree, as well as practically, for applications requiring real-time verification of streaming content.
Keywords :
cryptography; digital signatures; media streaming; mobile communication; trees (mathematics); wireless sensor networks; Merkle hash tree; hash path logarithm; leaf tree; low cost authentication; mobile device; per block digital signatures; per packet digital signatures; resource poor device; sensor device; streaming applications; streaming content; unbalanced authentication tree structure; unbalanced tree structure; Authentication; Delay; Digital signatures; Receivers; Vegetation; Content Authentication; Digital Signature; Merkle Tree;
Conference_Titel :
Sensor, Mesh and Ad Hoc Communications and Networks (SECON), 2012 9th Annual IEEE Communications Society Conference on
Conference_Location :
Seoul
Print_ISBN :
978-1-4673-1904-1
Electronic_ISBN :
2155-5486
DOI :
10.1109/SECON.2012.6275816