1. ENHANCED PRIVACY ID
A DIRECT ANONYMOUS ATTESTATION SCHEME WITH
ENHANCED REVOCATION CAPABILITIES
Under the Guidance of Ms. K.Revathi
Presented by:
 Zeeshan Afaque (1030920074)
 Sagar Gupta(1030920058)
 Sajid Mujtaba(1030920059)
 Shubham Chaturvedi(1030920075)

2. Explanation…
Direct Anonymous Attestation (DAA)
 Enables Remote Authentication of trusted platform.
 Preserves user privacy and Linkability.
 TPM proves validness to the remote requesting party.
 TPM can be revoked only if the DAA private key in
extracted
 Publishing of private key is necessary.
 TPM cannot be revoked if private key is not sent to
verifier

3. Abstract…
 A new Scheme can be developed called EPID( Enhances
privacy scheme).
 Provides Unlinkability in a more secure manner.
 TPM can be revoked even if the Private key is
unknown.
 No need to distribute the private key.
 Same security model as in DAA
 More efficient in exception handling than the
conventional DAA.

4. Terminologies…
 DAA : Direct Anonymous Attestation
 TPM : Trusted Platform Module
 EPID : Enhanced Privacy ID

5. Existing System…
o In DAA, an issuer creates group public key.
o TPM obtains unique key from the issuer.
o For authentication the TPM Generates a Signature.
o The verifier verifies the generated signature.
o If the TPM was found compromised, the private key is placed in the
revocation list.
o Verifier checks the signature against the Revocation list.
o The appropriate result is issued.

6. Proposed System…
 EPID is developed.
 Enhanced revocation capabilities.
 Broader capability beyond attestation and TCG(trusted computation group).
 Contains four Entities:
• Issuer.
• Revocation manager
• User
• Verifier
 The issuer can be the same entity as the revocation manager.
 The signatures must be:
 Unforgeable .
 Anonymous.
 Unlinkable.

7. Software Requirements…
 Operating System - Windows XP
 Platform - Visual Studio .NET 2008
 Database - SQL Server 2005
 Languages - Asp.Net , C#.Net

8. Hardware Requirements…
 Hard Disk - 20 GB
 Monitor - 15’ Color with VGI card support
 RAM - Minimum 1 GB
 Processor - Pentium IV and Above (or) Equivalent
 Processor Speed - Minimum 500 MHz speed

9. Algorithm…
EPID scheme consists of four procedures :
 Setup : The issuer creates a group
public key and a group issuing private key. The Issuer
publishes the group public key.
 Join : Protocol between the issuer and a user that
results in the user becoming a new group member. At the
end, the user obtains a membership private key from the
issuer.

10.  Proof of membership : A prover interacts with a
verifier to convince the verifier that he is a member of
the group by following ways-
 The prover sends a request to the verifier.
 The verifier responds with a message m.
 The prover generates a signature on m based on his
membership private key.
 The verifier verifies the signature using the group public
key.

11.  Revocation : The revocation manager puts a group
member into the revocation list. There are three types of
revocations:
 Private-key-based revocation in which the revocation
manager revokes a user based on the user’s membership
private key.
 Signature based revocation in which the revocation
manager revokes a user based on the signatures created
by the user.
 Issuer-based revocation in which the revocation manager
revokes a user based on the recommendation from the
issuer.

12. Thank you !!