Amount of spam in global free e mail services - simulation

Općenito besplatni svjetski servisi elektroničke pošte su lošijih sigurnosnih karakteristika u usporedbi s adresama elektroničke pošte institucije ili poslovne organizacije. Zbog toga je za očekivati kako će korisnik primati znatno više neželjene elektroničke pošte prilikom korištenja besplatnih svjetskih servisa elektroničke pošte. Kako bi primali neželjenu elektroničku poštu te usporedili količinu koju prima korisnik koristeći besplatnu odnosno institucijsku adresu, autori su simulirali dio komunikacije elektroničkom poštom koji se odnosi na registriranje na razne Internet servise. Iz rezultata simulacije čini se kako korisnici besplatnih svjetski poznatih servisa elektroničke pošte u prosjeku primaju značajno više neželjene elektroničke pošte. Simulacija je također pokazala značajnu razliku između samih besplatnih svjetskih servisa elektroničke pošte te očekivani porast količine neželjene elektroničke pošte s vremenom. S obzirom na rezultate simulacije te prijašnja istraživanja autori preporučuju korisnicima komunikacijskog sustava elektroničke pošte da za komunikaciju daju prednost institucijskim i korporativnim adresama, a pogotovo kad ih koriste za profesionalnu elektroničku komunikaciju.Usage of global free e mail services instead of institutional or company’s e mail addresses can more often cause security drawbacks. Regarding their weaknesses it can be assumed that there will be more unwanted e mails when using those addresses. In order to receive unwanted e mail and compare the amount that user receives at different e mail addresses the authors simulated part of e mail usage, the one when user registers on different Internet services. Results have shown that the users of the global free e mail services on average receive significantly more unwanted e mail compared to the users that use institutional or company’s e-mail address. There was also significant difference found among free global e mail services. Simulation has also shown increasing trend in amount of unwanted e mail received per month. Regarding these results and previous studies the authors’ advice is to prefer institutional or company’s e mail address over free global e mail services for Internet communication, especially when it is used for professional e mail communication

Some common attacks against certified email protocols and the countermeasures

Abstract: Certified email is a value-added service for standard email systems, which guarantees the fairness, i.e., the intended recipient gets the mail content if and only if the mail originator re-ceives a non-repudiation receipt showing that the message has been received by the recipient. As far as security is concerned, fairness is the most important requirements, though some other properties are also desirable in practice. Recently, a number of certified email protocols have been proposed. However, most of those schemes have more or less weaknesses and/or security flaws. In the worst case, fairness cannot be achieved since one dishonest party can mount some attacks to cheat the honest party such that the latter cannot get the expected items. In this paper, we analyze two latest certified email protocols to demonstrate some common attacks, and then propose some improvements to avoid those security problems. We further give several informal but useful guidelines to counter those common attacks in the design of certified email protocols

Keeping Fairness Alive : Design and formal verification of optimistic fair exchange protocols

Fokkink, W.J. [Promotor]Pol, J.C. van de [Promotor