  The emerging Internet of Things (IoTs) invokes increasing security demands
that require robust encryption or anti-counterfeiting technologies. Albeit
being acknowledged as efficacious solutions in processing elaborate graphical
information via multiple degrees of freedom, optical data encryption and
anti-counterfeiting techniques are typically inept in delivering satisfactory
performance without compromising the desired ease-of-processibility or
compatibility, thus leading to the exploration of novel materials and devices
that are competent. Here, a robust optical data encryption technique is
demonstrated utilizing polymer-stabilized-liquid-crystals (PSLCs) combined with
projection photoalignment and photopatterning methods. The PSLCs possess
implicit optical patterns encoded via photoalignment, as well as explicit
geometries produced via photopatterning. Furthermore, the PSLCs demonstrate
improved robustness against harsh chemical environments and thermal stability,
and can be directly deployed onto various rigid and flexible substrates. Based
on this, it is demonstrated that single PSLC is apt to carry intricate
information, or serve as exclusive watermark with both implicit features and
explicit geometries. Moreover, a novel, generalized design strategy is
developed, for the first time, to encode intricate and exclusive information
with enhanced security by spatially programming the photoalignment patterns of
a pair of cascade PSLCs, which further illustrates the promising capabilies of
PSLCs in optical data encryption and anti-counterfeiting.
