Security scheduling and transaction mechanism of virtual power plants based on dual blockchains

Journal of Cloud Computing

Advances, Systems and Applications

Table 5 Comparison of communication overhead

Scheme	System parameters	Encryption key	Ciphertext	Re-encrypted ciphertext
Ref. [47]	8\|G\|+2\|G_T\|	(2\|S\|+4)\|G\|	(2\|l\|+5)\|G\|+\|G_T\|	(2\|I\|+8)\|G\|+3\|G_T\|
Ref. [48]	(8\|U\|+6)\|G\|+\|G_T\|	6\|S\|\|G\|	(6\|l\|+2)\|G\|+\|G_T\|	2\|G\|+(2\|I\|+1)\|G_T\|
Ref. [49]	6\|G\|+\|G_T\|	(\|S\|+2)\|G\|	(3\|l\|+3)\|G\|	6(\|I\|+1)\|G\|+\|G_T\|
Our scheme	6\|G\|+\|G_T\|	(\|S\|+2)\|G\|	(3\|l\|+2)\|G\|+\|G_T\|	4\|G\|+\|G_T\|

|G|, |G_T|: the lengths of the cyclic groups G and G_T; |U|: the attribute complete set size; |S|: the user attribute set size; |l|: the number of attributes in the access structure; |I|: the number of attributes that satisfy the access structure

Scheme	System parameters	Encryption key	Ciphertext	Re-encrypted ciphertext
Ref. [47]	8\|G\|+2\|G_T\|	(2\|S\|+4)\|G\|	(2\|l\|+5)\|G\|+\|G_T\|	(2\|I\|+8)\|G\|+3\|G_T\|
Ref. [48]	(8\|U\|+6)\|G\|+\|G_T\|	6\|S\|\|G\|	(6\|l\|+2)\|G\|+\|G_T\|	2\|G\|+(2\|I\|+1)\|G_T\|
Ref. [49]	6\|G\|+\|G_T\|	(\|S\|+2)\|G\|	(3\|l\|+3)\|G\|	6(\|I\|+1)\|G\|+\|G_T\|
Our scheme	6\|G\|+\|G_T\|	(\|S\|+2)\|G\|	(3\|l\|+2)\|G\|+\|G_T\|	4\|G\|+\|G_T\|