Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Provably Secure Certified Mail

B. Pfitzmann, Matthias Schunter, Michael Waidner

Published Jan 1, 2000• 14 citations
OpenAlex

Abstract

With a certified-mail protocol, one fairly exchanges a message for a receipt. No satisfactory protocols without any third party are possible, hence optimistic protocols are the best one can hope for. Here a third party is only involved if one party tries to cheat. Certified-mail protocols are known in the literature, but there was no rigorous definition yet, in particular for the optimistic case and for many interleaved executions. We provide two such definitions. One defines individual integrity and secrecy requirements. The other defines an ideal system and uses a general simulatability definition. We show the relation between the definitions, present an efficient protocol, and prove its security in detail. Apart from the intrinsic benefits of provably secure certified mail, this paper serves as an example that a serious-sized practical protocol can be rigorously proven with respect to a general simulatability definition and an abstract specification accessible to formal me...

Related papers

Reactively Simulatable Certified Mail.

Birgit Pfitzmann, Matthias Schunter, Michael Waidner

Abstract Certified mail is the fair exchange of a message for a receipt, i.e., the recipient gets the message if and only if the sender gets a receipt. It is an important primitive for electronic commerce and other atomicity services. Certified-mail protocols are known in the literature, but there was no rigorous definition yet, in particular for optimistic protocols and for many interleaved executions. We provide such a definition via an ideal system and show that a specific real certified-mail protocol is as secure as this ideal system in the sense of reactive simulatability in the standard model of cryptography and under standard assumptions. As certified mail without any third party is not practical, we consider optimistic protocols, which involve a third party only if one party tries to cheat. The real protocol resembles prior protocols, but we had to use a different cryptographic primitive to achieve simulatability. The communication model is synchronous. This proof first demonstrated that a cryptographic multi-step protocol can fulfil a general definition of reactive simulatability enabling concurrent composition. We also first showed how formal-method style reasoning can be applied over the ideal system in a cryptographically sound way. Moreover, the treatment of multiple protocol runs and their modular proof in spite of the use of common cryptographic primitives for all runs can be seen as a first example of what is now known as joint-state composition.

•Jan 1, 2006•2 citations

An Efficient Certified E-Mail Scheme Suitable for Wireless Mobile Environments

Guilin Wang, Feng Bao, Jianying Zhou +1 more

As security enhanced systems for standard e-mail, certified e-mail schemes guarantee the fair exchange of a digital message with the corresponding receipt between two mistrusted parties. That is, the intended receiver gets the e-mail content if and only if the e-mail sender obtains an irrefutable receipt issued by the receiver, which could be used to prove that the message has been delivered to the receiver. A number of such protocols have been proposed in recent years. However, most of them are not suitable for mobile networks, since many intricate cryptographic primitives are involved so that considerable overheads are introduced. In this paper, we present a novel simple protocol for certified e-mail delivery. Technical discussions are provided to show that our new solution is both secure and very efficient so that it is truly suitable for wireless mobile users, where the available devices usually have limited resources on computation, communication, storage, and power supply.

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)•Aug 2, 2006•3 citations

Verifiable encryption of digital signatures and applications

Giuseppe Ateniese

This paper presents a new simple schemes for verifiable encryption of digital signatures. We make use of a trusted third party (TTP) but in an optimistic sense, that is, the TTP takes part in the protocol only if one user cheats or simply crashes. Our schemes can be used as primitives to build efficient fair exchange and certified e-mail protocols.

ACM Transactions on Information and System Security•Feb 1, 2004•96 citations

Certified Mail Protocols by Using Signcryption System

Wang Gai-fen

Certified mail protocol is fair exchange of a message M for a receipt.Fairness is the most important property in exchange.We modify existing signcryption system so that it can be used by certified mail protocols,and based on the system we propose new certified mail protocols to guarantee fairness and low computation cost.

Dianzi xuebao•Jan 1, 2003•0 citations

A New Certified E-Mail Protocol Based on Signcrytion

Wen Qiao-yan

A certified e-mail protocol is about fair exchange of a message m for its receipt. Fairness is the most important property in exchange. We modify existing W-B signcryption scheme so that it can be used by certified e-mail protocols,and based on the modified scheme we propose a new certified e-mail protocol. The protocol makes use of an off-line and transparent trusted third party only in exceptional circumstances,and has lower computation overhead and better efficiency comparing related protocol.

Dianzi Ke-ji Daxue xuebao•Jan 1, 2008•1 citation

A security protocol for certified e-goods delivery

Aleksandra Nenadić, Ning Zhang, S. Barton

This paper presents an efficient security protocol for certified e-goods delivery with the following features: (1) ensures strong fairness, (2) ensures non-repudiation of origin and non-repudiation of receipt, (3) allows the receiver of an e-goods to verify, during the protocol execution, that the e-goods he is about to receive is the one he is signing the receipt for, (4) does not require the active involvement of a fully trusted third party, but rather an off-line and transparent semi-trusted third party (STTP) only in cases of unfair behaviour by any party, and (5) provides confidentiality protection for the exchanged items from the STTP.

International Conference on Information Technology: Coding and Computing (ITCC)•Jan 1, 2004•16 citations
With a certified-mail protocol, one fairly exchanges a message for a receipt. No satisfactory protocols without any third party are possible, hence optimistic protocols are the best one can hope for. Here a third party is only involved if one party tries to cheat. Certified-mail protocols are known in the literature, but there was no rigorous definition yet, in particular for the optimistic case and for many interleaved executions. We provide two such definitions. One defines individual integrity and secrecy requirements. The other defines an ideal system and uses a general simulatability definition. We show the relation between the definitions, present an efficient protocol, and prove its security in detail. Apart from the intrinsic benefits of provably secure certified mail, this paper serves as an example that a serious-sized practical protocol can be rigorously proven with respect to a general simulatability definition and an abstract specification accessible to formal me...
Abstract Certified mail is the fair exchange of a message for a receipt, i.e., the recipient gets the message if and only if the sender gets a receipt. It is an important primitive for electronic commerce and other atomicity services. Certified-mail protocols are known in the literature, but there was no rigorous definition yet, in particular for optimistic protocols and for many interleaved executions. We provide such a definition via an ideal system and show that a specific real certified-mail protocol is as secure as this ideal system in the sense of reactive simulatability in the standard model of cryptography and under standard assumptions. As certified mail without any third party is not practical, we consider optimistic protocols, which involve a third party only if one party tries to cheat. The real protocol resembles prior protocols, but we had to use a different cryptographic primitive to achieve simulatability. The communication model is synchronous. This proof first demonstrated that a cryptographic multi-step protocol can fulfil a general definition of reactive simulatability enabling concurrent composition. We also first showed how formal-method style reasoning can be applied over the ideal system in a cryptographically sound way. Moreover, the treatment of multiple protocol runs and their modular proof in spite of the use of common cryptographic primitives for all runs can be seen as a first example of what is now known as joint-state composition.
As security enhanced systems for standard e-mail, certified e-mail schemes guarantee the fair exchange of a digital message with the corresponding receipt between two mistrusted parties. That is, the intended receiver gets the e-mail content if and only if the e-mail sender obtains an irrefutable receipt issued by the receiver, which could be used to prove that the message has been delivered to the receiver. A number of such protocols have been proposed in recent years. However, most of them are not suitable for mobile networks, since many intricate cryptographic primitives are involved so that considerable overheads are introduced. In this paper, we present a novel simple protocol for certified e-mail delivery. Technical discussions are provided to show that our new solution is both secure and very efficient so that it is truly suitable for wireless mobile users, where the available devices usually have limited resources on computation, communication, storage, and power supply.
A certified e-mail protocol is about fair exchange of a message m for its receipt. Fairness is the most important property in exchange. We modify existing W-B signcryption scheme so that it can be used by certified e-mail protocols,and based on the modified scheme we propose a new certified e-mail protocol. The protocol makes use of an off-line and transparent trusted third party only in exceptional circumstances,and has lower computation overhead and better efficiency comparing related protocol.
This paper presents an efficient security protocol for certified e-goods delivery with the following features: (1) ensures strong fairness, (2) ensures non-repudiation of origin and non-repudiation of receipt, (3) allows the receiver of an e-goods to verify, during the protocol execution, that the e-goods he is about to receive is the one he is signing the receipt for, (4) does not require the active involvement of a fully trusted third party, but rather an off-line and transparent semi-trusted third party (STTP) only in cases of unfair behaviour by any party, and (5) provides confidentiality protection for the exchanged items from the STTP.