I read the summary of deniable encryption on wikipedia:
Then I read a question, by
doom123 on security.SE:
But I had a subtly different problem which can be stated as follows:
- Alice wants to send Bob the book "Mocking Jay" which is banned in Bob's country.
- Alice encrypts "Mocking Jay" to data
MJwith the password
- Using another book of similar size (or by trimming a larger book), say the "The Hobbit", she processes the data
MJand computes password
The solution to this problem will allow Bob to claim that he maintains a copy of "The Hobbit" (assuming that "The Hobbit" is not banned of course), while being able to read "Mocking Jay". The solution, in theory, should also allow Bob to plausibly deny that there's any other copy hidden in the data "MJ" other than "The Hobbit"; or like the aforementioned security.SE question, should allow "MJ" to hold any number of copies (and thus any number of passwords), providing Bob the excuse of acknowledging only one copy that he has the knowledge of.
The answer provided by the user
lynks to the question posed by
doom123 solves the problem for storing data on a hard-disk. Is there a general solution to this problem?
With regards to the answer provided by
fgrieu I am slightly modifying the question. Is it possible to add a third layer (and an arbitrary number of further layers) of such encryption? What I mean is, with
The Hobbit, and
Silmarillion (assuming that the books are roughly the same in size) as inputs, is it possible to create an encrypted output say
MJTHSI? I am alright with the passwords being the output as well. Decrypting with password
P1 will reveal
Mocking Jay. If rubber-hose is used password
P2 can also be given up revealing
The Hobbit (with the intention of ultimately protecting
Silmarillion which can be revealed using