It is of critical importance to design digital identity systems that ensure the privacy of citizens as well protect them from state corruption as the identity issuer. Unfortunately, what Europe and USA state organizations are currently developing does not offer such basic protections. As a solution we introduce a method for untraceable selective disclosure and privacy preserving revocation of digital credentials, utilizing the unique homomorphic characteristics of second order Elliptic Curves and Boneh-Lynn-Shacham (BLS) signatures operated on them. Our approach ensures that users can selectively reveal only the necessary attributes, while protecting their privacy across multiple presentations and against colluding verifiers. Since we also want to protect users from issuer corruption, we apply a threshold for credential issuance and revocation to mandate a collective agreement among multiple issuers. Finally, our method of revocation does not give out any information on the identity of holders of revoked credentials.

Add any reference used in text inside the references.bib file in BibTeX format.

Add references inside the text using the \cite{..} tag, i.e. \cite{bls381-12} for the article named bls381-12 inside the references.bib file.

Do an apt-get install of the following packages:

 texlive-extra-utils texlive-latex-recommended texlive-font-utils \
 texlive-fonts-extra texlive-latex-extra texlive-fonts-recommended \
 texlive-science poppler-utils epstool

Then do make to build the latest sd-bls.pdf from this repo.