Table 1 Correlation coefficients of adjacent pixels.
From: Asymmetric cryptosystem based on optical scanning cryptography and elliptic curve algorithm
Correlation coefficients | Plaintext | Cosine hologram | Sine hologram | Ciphertext | |
|---|---|---|---|---|---|
\({{\varvec{c}}}_{{\varvec{x}}}\) | \({{\varvec{c}}}_{{\varvec{y}}}\) | ||||
Horizontal | 0.9804 | 0.9853 | 0.9278 | 0.0016 | 0.0064 |
Vertical | 0.9637 | 0.9764 | 0.8375 | –0.0042 | –0.0014 |
Diagonal | 0.9578 | 0.9706 | 0.8374 | 0.0169 | 0.0131 |
