Abstract: A series of data treatment processes, software applications and hardware devices jointly used to achieve the ability to make an electronic document available to the public or to a limited audience to either cease being readable, or start being readable, at a given moment in time or after a given event has occurred. A typical usage scenario consists in “automatic destruction” of documents used internally by an organization and that must be made unreadable after a certain project is complete. Conversely, public offers for auctions may be posted to all the participants and the issuer in an unreadable form, and made then readable after the deadline of the auction is expired. Again, documents may be made unreadable after a certain number of reads, or forwarded to a specific address under some conditions, or accessed only through well-known unmodified clients.