REG_BINARY values are usually not encrypted. The easiest way I can think to get a text string that describes a REG_BINARY value would be unpack, which could give you, for example, a hexadecimal dump via: $hex = unpack "H*", $binary;

Of course, I am assuming that you already have code that gets the REG_BINARY value into $binary. If not, I'd use Win32::TieRegistry (but maybe I'm biased).