Research Article
Cryptanalysis and Improvement of Chaos-Based Image Encryption Scheme with Circular Inter-Intra-Pixels Bit-Level Permutation
Table 2
NPCR and UACI values of different images by different algorithms.
| Image | NPCR (%) | Ref. [21] | Ref. [22] | Ref. [23] | Original | Improved |
| Lena | 99.61 | 99.55 | 99.61 | 99.62 | 99.60 | Peppers | 99.61 | 99.58 | 99.62 | 99.61 | 99.61 | Couple | 99.63 | 99.56 | 99.63 | 99.63 | 99.64 | Cameraman | 99.63 | 99.57 | 99.61 | 99.60 | 99.63 | Boat | 99.63 | 99.56 | 99.62 | 99.61 | 99.59 |
| Image | UACI (%) | Ref. [21] | Ref. [22] | Ref. [23] | Original | Improved |
| Lena | 33.56 | 33.34 | 33.63 | 33.48 | 33.47 | Peppers | 33.63 | 33.35 | 33.74 | 33.51 | 33.40 | Couple | 33.64 | 33.37 | 33.72 | 33.49 | 33.45 | Cameraman | 33.71 | 33.37 | 33.69 | 33.52 | 33.59 | Boat | 33.61 | 33.42 | 33.60 | 33.49 | 33.32 |
|
|