Image overlay for duplicate image detection

Image overlay for duplicate image detection

Forgery and falsification prevention device

Method of authenticating an item

Image overlay for duplicate image detection

Diffractive device

Optically variable entity authenticating device and method

Method and device for authenticating a tag

Active images through digital watermarking

Method for the authentication and/or identification of a security item

Moire magnification device

Moire magnification device

Moire magnification device