Take the 2-minute tour ×
Cryptography Stack Exchange is a question and answer site for software developers, mathematicians and others interested in cryptography. It's 100% free, no registration required.

I would like to inquire if there is any Method to achieve the following:

There is a list $L$ of $n$ entities that are allowed to perform a certain action. $L$ is cryptographically signed by some authority, so nobody can change it without detection. Now everybody (icluding everyone of the $n$ entities) should be able to grab a copy of $L$ and mirror it.

Is there any method one can devise a scheme, where everyone who holds a copy of $L$ can authenticate one of the $n$ entities. (for Example with a blind signature, or similar), without giving the mirroring Person the power to authenticate someone, who is not part of $L$.

Example: Some authority releases $L = [Alice,Bob,Charlie]$. Now $Dennis$ takes a copy of $L$. How can I assure, that $Dennis$ can authenticate $Alice$ but not $Eve$?

share|improve this question
    
Either [[the authority's key pair has a very special form] and [the authority gives each of those entities a secret in a confidential manner] and [it's not a problem that the authority can have itself be authenticated as any of those users]] or [[the $n$ entities each generate a key-pair for public-key authentication] and [the $n$ entities each give their public key to the authority in an authentic manner] and [the authority signs the list of $\: \langle $identity , public_key$\rangle \:$ instead of $L\hspace{.02 in}$]]. $\;\;\;$ –  Ricky Demer Mar 25 at 7:17

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.