Schemes

Security level

Limitations

heading Vikas et al. [13]

Authenticate the identity of the e-mail sender

The distribution of public key is

by checking the header field of the message

a legitimate binding to its owner.

Hameed et al. [8]

Authenticate the identity by providing signature

iSAT has low computational footprints

to provide easy and reliable approach to combine

footprints and overhead is imposed.

the legitimate sender identity unambiguously to

his e-mails

Mooloo et al. [14]

Provide authentication by using cryptographic

To receive a confirmation message

self-signed certificates for exchange a secure

to the client computers have to be

authentication message alongside the a e-mail

turned on and the application should

with already be running vision to avoid spoofing.

already be running

Kounelis et al. [15]

Protection of e-mails, privacy of locations from

The proxy server represents a single