Pixel Picture Element
Pixels to form the graphic image of a point.

PKI Public Key Infrastructure
PKI is a private key and public key by including the composition of online security mechanisms to ensure that the payment stream on the network and information flow, and the identity of covert non-repudiation.
The purpose of PKI is to build secret or public environment, providing a trusted and efficient key and certificate management, its functions include the proceeds of the privacy of data encryption (Confidentiality), arising from the use of electronic signature Non-repudiation (non-repudiation) and the information and data consistency (Integrity) to verify, as well as certification with the golden key, key holder, application, authentication services, access control to provide authentication.
The most important thing is, whether the public key or private key chosen by the geometric methods produce a certain bit length (such as the 64,128 bit), to ensure that the crack is not easy being the technical difficulty.
After the public key is just a third party mechanisms (including government, banking, general corporate, etc.) to authenticate the establishment of certification center, the private key by the parties to the transaction, one party to another request made not to share a third party.
PKI using a combination of public and private key with encryption and identity authentication function. Sending messages on the sender to key encryption, the requirements of the receiving person's private key to decrypt; while the sender to send e-signature, then the private key is encrypted with the recipient public key to decrypt.
PKI is a non-equilibrium type of encryption (ie encryption and decryption do not use the same key) is currently recognized than SSL, and balance of encryption is more effective. With the popularity of electronic and online transactions, the demand for PKI has also risen. A similar role, and PKI technologies, including VPN and IP sec (IP security).

PKZIP Software
Common file compression software, compression file extension is usually ZIP.

Platform
Platform, the computer system used by the operating system (OS) or hardware.