Although not strictly linked to remote computing many different aspects in our day-to-day operations involve remote transferring of information, as well as, remote access, trust, etc. Among one of the most relevant tools and commodities employed nowadays is electronic-mail, e-mail.
In security, a firewall is a system that controls the incoming and outgoing information into a system. They offer a way to guard, inspect and filter the information flow into the system. Firewalls can be implemented in hardware or software. Hardware firewalls are mostly used at the level of data centers or Internet service providers, they suppose to act as a general and broad filter of generic attacks, such as denial of service or brute force attacks. Software firewalls can be also configured by centralized authorities, as well as by users in their own local systems. Examples of this, are the usual firewall settings at level of the OS -- it is strongly recommended to adjust these settings consciously to minimize the inflow or outflow of unnecessary information.
In the same way that it is important to validate the integrity and validity of our connections to remote systems, it would also be for other types of communications, such as electronic messages, or email. In particular, for email a tool called Pretty Good Privacy (PGP) can be used to ensure the confidentiality %of the messages exchanged, as well as validate the identity of the sender. PGP is an encryption method that provides cryptographic privacy and authentication for data communication. The basic idea is to encrypt the communication (similar to how using ssh-keys would do it) and sign it so that the message received at the other end of the communication channel can be decrypted, validated and authenticated.
Based on the principles of keys (such as the ssh-keys), are an alternative to the use of passwords for authentication. Their use relies on the implementation of a given application capable of handling them.
Last Modified: Jul 13, 2023 -- v 1.0