Self-Healing Group Key Distribution Facilitating Source Authentication Using Block Codes

Table 2

Comparison of the functionalities of the related schemes.

Scheme	No. of revoked users	Authorized group	Revoked users rejoining a later session	Source authentication	Self-healing	Other key features
[12, 13]	Predetermined before deployment	Not flexible	Not allowed	Not provided	Yes	US
[14]	Predetermined before deployment	Not flexible	Not allowed	Not provided	Yes	US
[3, 19]	Predetermined before deployment	Not flexible	Not allowed	Not provided	Yes	CS
[39]	Predetermined before deployment	Not flexible	Yes but with different identity	Not provided	Yes	CS
[27]	Not predetermined	Flexible	Allowed	Not provided	Yes	CS; GKUPMC
[29]	Not predetermined	Flexible	Allowed	Not required^1	Not consider	HKS; GKUMCSC.
[30]	Not predetermined but the number of group members is predetermined	Flexible	Allowed	Not provided	Not consider	PDGKM; GKUMC; the size of the encryption expands linearly with the number of the members
[32]	Not predetermined	Flexible	Allowed	Not provided	Mutual healing^2	GKUMC
[31]	Not predetermined	Flexible	Allowed	Not provided	Not consider	GKUMC
[26]	Not predetermined	Flexible	Allowed	Not provided	Yes	GKUMC
[21]	Predetermined	Not flexible	Not allowed	Not provided	Yes	GKUMC
[22]	Predetermined	Not flexible	Not allowed	Not provided	Yes	GKUPMC
Ours	Not predetermined	Flexible	Allowed	Provided	Yes	GKUPMC

In a pay-TV system, there is only one message source. A node can recover the lost keys from the ground station and the neighbors. CS: computationally secure; US: unconditionally secure. GKUMC: Group Key Updating triggered by Membership Change; GKUPMC: Group Key Updating Periodically and triggered by Membership Change; GKUMCSC: Group Key Updating triggered by Membership Change and Subscription Change; HKS: Hierarchical Key Structure; PDGKM: Partially Distributed Group Key Management.