Collaborative working environment with defined subgroup of users

Computer workstation 100 for use in a shared virtual working environment with networked computer workstations (100), (120), (140) comprising: a network interface 105 for communicating with other computer workstations; a display controller 106 for displaying a visual representation of the shared virtual working environment; a user interface controller 107 for receiving a user input to define a subgroup of users; and a subgroup controller 102 for setting up a subgroup workspace being accessible only to said subgroup of users, and for enabling sharing of files or data allocated to the subgroup with the other users. Said visual representation comprises a shared virtual desktop which displays public and private workspaces as tiles differentiated by means of colour coding. High or low resolution areas for display or parking of documents can also be provided, respectively. Annotations are saved as overlay for shared documents and sent to other subgroup users. Data encryption is provided via secure digital containers with multiple security levels. A description key for said container can be generated and distributed by an authorisation server.