Perfect Computer Notes

What are commonly used units of measuring storage? Bit Bit is a short for Binary Digit. 0 and 1 are the only binary digits. Bit is the smallest unit of measuring storage capacity. A bit can hold a 0 or 1. Byte A combination of 8 bits is called a Byte. A byte can hold one character. 1 Byte = 8 bits Kilobyte (KB) 1024 bytes make one kilo byte. Kilo Byte is denoted by KB. 1 KB = 1024 Bytes Megabyte (MB) 1024 Kilo bytes make one mega byte. Mega Byte is denoted by MB. 1 MB = 1024 KB Gigabyte (GB) 1024 mega bytes make one Giga byte. Giga Byte is denoted by GB.  1 GB = 1024 MB Terabyte (TB) 1024 Giga bytes make one Tera byte. Tera Byte is denoted by TB.  1 TB = 1024 GB Petabyte (PB) 1024 Tera Bytes make one Peta byte. Peta Byte is denoted by PB.  1 PB = 1024 TB Exabyte (EB) 1024 Peta bytes make one Exa byte. Exa Byte is denoted by EB.  1 EB = 1024 PB

What are different security protocols for e-payment security schemes? 1. SSL Protocol (Secure Sockets Layer Protocol) SSL (Secure Sockets Layer) is the standard security protocol for establishing an encrypted link between a web server and a browser. This link ensures that all data passed between the web server and browsers remain private and integral. SSL is used by millions of websites in the protection of their online transactions with their customers. SSL or Secure Sockets Layer is a security protocol created by Netscape that has become an international standard on the Internet for exchanging sensitive information between a website and the client computer. SSL technology is embedded in all popular browsers and engages automatically when the user connects to a web server that is SSL-enabled. It's easy to tell when a server is using SSL security because the address in the URL window of your browser will start with https. The "s" indicates a secure connection.

Explain E-payment Security Schemes Following are the e-payment security schemes 1) Encryption 2) Certificates & Certificates Authority (CA) 3) Digital Signature 4) Digital Envelop 5) Message Digest 6) Transaction Certificates and Time Stamp (1) Encryption Encryption refers to changing a message into unreadable form. Later the encrypted message can be converted into readable form by Decryption. There are two types of Encryption (A) Secret Key Encryption/Private Key Encryption In this scheme, same key called secret key is used by sender and receiver for Encryption (Making message unreadable) & Decryption (Getting original message). Data Encryption Standards (DES) is the most widely used algorithm for secret key/private key encryption scheme. (B) Public Key Cryptography It is Also known as asymmetric Encryption. It uses two different keys (1) Private Key (2) Public Key. The receiver sends his public key to sender. The sender encrypts message with thi