All login credentials transferred over plain HTTP can easily be sniffed by an MITM attacker, but is is not enough to encrypt the login forms. If you are visiting plain HTTP pages while logged in, your session can be hijacked, and not even two-factor authentication will protect you. To protect all info sent between your visitors – which includes you – and your web server, we will redirect all requests that are coming over plain HTTP to the HTTPS equivalent.
It is not really necessary to use HTTPS for absolutely all requests, but it makes your life much easier to just handle one scheme and redirect all plain HTTP traffic to the equivalent HTTPS resource. So please make sure you setup HTTPS for the same hostname that you use for plain HTTP. Do NOT use
secure.example.com if your regular hostname is
www.example.com. The only difference should be the scheme – nothing else. This will save you from a lot of headaches further down the road. Continue reading “Redirect HTTP requests to HTTPS with Nginx”
A power supply is used to operate the electrical power for the equipment that may not be connected directly to the 220V socket, but require a different voltage, typically much lower, similar to that provided by batteries.
To make sure that the alternating voltage provided in the outlets of the house be equal to that of a battery, the power supply uses several components, each with a specific function: we will see what are these components, examining the construction of the simplest of the power supplies. Continue reading “How to build a Power Supply”
The term “LED” is an acronym that stands for “Light Emitting Diode“. The LEDs are constituted by a P-N junction realized with gallium arsenide or gallium phosphide, both of materials able to emit light when they are traversed by an electric current; the value of this current is between 10 and 30 mA. Continue reading “LED Diode”
On the “The diode as rectifier” there has been a talk of the inversely polarized diode behavior; it is seen that, by applying a positive voltage to the cathode than the anode, a current flows only very weak, said “drift current“, until the applied voltage reaches a value such as to trigger the “avalanche effect“. Working in such conditions, a normal diode comes early to destruction by overheating. Continue reading “The zener diode”
An electronic component from the very peculiar behavior is the diode. We have seen that applying a certain voltage to a resistor, the current through it corresponds to the ratio between the applied voltage and the resistance value of the same; this law does not apply to the diode. Continue reading “The diode as rectifier”
Telecommunications means remote transmission of information.
At the dawn of human civilization, to communicate was used smoke signals, the mirrors that reflected the sun’s rays, then the couriers on horseback, pigeons, and so on, but you can really talk about long distance transmission of information, both well as on cable, only with the invention of the TELEGRAPH and the MORSE code occurred in America in 1837 by Samuel Morse, painter and inventor, which allowed to transmit signals with a dot and line code through the prairie of the Wild West by using a single copper wire supported by wooden poles. Continue reading “The Origins of Telecommunications”
SSH (Secure shell ) is a UNIX based command line and protocol for remotely connecting to the machines in a secure way. Authentication process it is validated via a digital certificate from both sides.
Ssh can be used to connect from cross platform FTP like filezilla, winscp etc avoiding connecting In a non secure way via ftp, so in this way we can upload, download files from the web server without getting hacked.
Ssh secure the connection via symmetrical, asymmetrical encryption and hashing. Continue reading “SSH Protocol”