Substitution and transposition ciphers are two categories of ciphers used in classical cryptography. Substitution and transposition differ in how chunks of the message are handled by the encryption process. Substitution ciphers Substitution ciphers encrypt plaintext by changing the plaintext one piece at a time. The Caesar Cipher was an early substitution cipher. In the Caesar …
PKI Authorities consists of three different authorities that essentially make up a PKI system. These are the Registration Authority, Certification Authority and Certificate Directory. Registration Authority The jobs of the Registration Authority are to processes user requests, confirm their identities, and induct them into the user database. Certification Authority The tasks of a Certification Authority …
One of the most common hardware problems that people who own a laptop experience is a broken or malfunctioning laptop screen. Laptop screens are essential to laptop use. Laptop screens can be incredibly delicate. However, they are surprisingly very easy to fix even if the fixer is not a technical person. Troubleshoot the Laptop Screen …
Information technology group Wi-Fi Alliance or WFA has been testing a next generation, yet still pre-standard wireless networking program that would define wireless Internet of the future. Much ado has been tackled about the technology called 802.11n. For the average Internet user, who knows not too much about the standards and technicalities of the information …
Databases are collections of organized information. The data is normally organized to help model the aspects of the information in a manner that support processing requests for information in a useful manner. A DBMS (database management system) is an application that is designed specifically to interact with the end-user, the database of information, and other …
Microsoft PowerPoint documents can utilize two passwords: Password to open Password to modify Password to open The Password to open requires a user to enter a password to view the document. When the user sets a Password to open, the entire Microsoft PowerPoint document is encrypted with the RC4 stream cipher. Password to modify The …
MSOCACHE (Local Install Source) is a setup feature that Microsoft deploys with Microsoft Office 2003. It is a hidden folder that is installed on the target computer’s local hard drive. It can occupy up to 290 Megabytes (MB) of space depending on the Microsoft Office programs that are installed on the computer. This feature eliminates …
When a computer reaches a point where it can no longer be repaired because of viruses and malware, or it has gotten to the point where more time is spent trying to load a page than you spend using it, the time might be to do a factory restore of the computer. What this means …
An IBM ThinkPad laptop can have three hardware password sets: Power-On Password Hard Disk Password Supervisor Password Power-On Password RT/CMOS RAM has 8 bytes reserved for the power-on password and the check character. The 8 bytes are initialized to hex 00. The microprocessor can access these bytes only during POST. After POST is completed, if …
Credit cards use the Luhn Check Digit Algorithm. The main purpose of the Luhn Check Digit Algorithm is to catch data entry errors, but it does double duty here as a weak security tool. The Luhn Check Digit Algorithm For a card with an even number of digits, double every odd numbered digit (1st digit, …