“…[23][24][25], we set at a fixed position a focus tunable lens, f v , and a CMOS camera-atz o and z z o r + from the object, respectively, figure 1(a). By tuning the lens to different focal length values, f f f , ,..., N 0 }, multiple intensity distributions of the speckle field (delocalized ciphertext) are sampled at a single plane (improving recording times).…”