authentication and session key establishment using a third-party medical server while the privacy of the patient can be ensured. In this paper, we propose an anonymous three-party password-authenticated key exchange (3PAKE) protocol for TMIS. The protocol is based on the efficient elliptic curve cryptosystem

is a newer approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields, and considered a s a marvelous technique with low key size for the use r, and hard exponential time challenge for an intruder to break into the system. In ECC a 16 0 bits key, provides

). Elliptic curve cryptosystem provides greater security compared to integer factorization system and discrete logarithm system, for any given key size and bandwidth. In our scheme, using ECC and then applying the knapsack generates the signature. Our scheme is secure against most of the current attacking

-key setting is the authenticity of the public key; this issue can be resolved by identity-based (ID-based) cryptography where the public key of a user can be derived from public information that uniquely identifies the user. This paper presents an encryption mechanism based on the ID-based scheme using

-key setting is the authenticity of the public key; this issue can be resolved by identity-based (IDbased) cryptography where the public key of a user can be derived from public information that uniquely identifies the user. This paper presents an encryption mechanism based on the IDbased scheme using Elliptic

I would like to thank some people who were involved in the creation of this thesis: • Berry Schoenmakers of TU Eindhoven for introducing me to the topic of cryptographic voting protocols. • Evangelos Karatsiolis for his work in guiding me through the process of writing this thesis and his constant motivation. • Roberto Samarone Araujo for hours of discussing various protocols with Evengelos and me. • Warren D. Smith for providing with a preliminary version of his upcoming book »How Mathematics can Improve Democracy«. • Ute Günther and Christian Burgmann for their proof-reading. Nonetheless, any remaing errors shall be blamed on me. • Andrea Peter for her love and for cheering me up when I was down. • Last but not least my parents, Jacqueline Herrnkind and Hans Peter Klink – without their love and continuous support, this thesis would never have been written.

pages 156–175, 2013. [2] Johannes Buchmann, Denise Demirel, and Jeroen van de Graaf. Towards a publicly-verifiable mix-net providing everlasting privacy. In Financial Cryptog-raphy, pages 197–204, 2013. [3] Denise Demirel, Jeroen van de Graaf, and Roberto Araùjo. Improving helios