PKI是（）。A、Private Key InfrastructureB、Public Key InstituteC、Public Key Infrastructure公钥基础设施D、Private Key Institute

Public Key Infrastructure(PKI) service providers offer organizations fully integrated PKI-managed services designed to secure Intranet, Extranet, Virtual Private Network(VPN), and e-commerce applications. PKI solutions can enable a number of security services, including strong authentication and non-repudiation of transactions.eToken enables the users of PKI systems to generate and store(101)and digital certificates inside the token, creating a secure environment and allowing full portability and maximum ease of use. eToken Pro can also perform. sensitive on-chip(102)operations, ensuring that users' keys axe never exposed to the PC environment, eToken eliminates the need to store(103)and keys on a hard disk or browser file, or to transmit them across the Internet/Extranet; assuring peace-of-mind and confidence during online communications.A digital signature is created using the private key of an individual to ensure the Validity of his request. This technology can be used to guarantee(104)of various transactions. The strength of either the authentication level or the digital signature relies on the level of protection offered to the private key. eToken Pro offers the maximum level of security, since it enables the use of the private key for signing and authenticating inside the eToken.The most secure use of authentication involves enclosing at least one certificate with every signed message. The message(105)verifies the certificate using the CA's public key. If the sender's public key is legitimate, the recipient verifies the message's signature. Digital signatures created with a private key are verified with the digital certificate containing the public key.

A．private keys

B．public keys

C．authentication codes

D．message digests

Symmetric, or private-key, encryption is based on a secret key that is shared by both communcating parties. The （ ） party uses the secret key as part of the mathematical operation to encrypt （ ） text to cipher text. The receiving party uses the same secret key to decrypt the cipher text to plain text. Asymmetric, or public-key, encryption uses two different keys for each user: one is a （ ） key known only to this one user; the other is a corresponding public key, which is accessible to anyone. The private and public keys are mathematically related by the encryption algorithm. One key ia used for encyption and the other for decryption, depending on the nature of the communication service being implemented. In addition, public key encryption technoligies allow digital （ ） to be placed on messages. A digital signature uses the sender&39;s private key to encrypt some portion of the message. When the message is received, the receiver uses the sender&39;s （ ） key tp decipher the digital signature to verify the sender&39;s identity.

A.host B.terminal C.sending D.receiving A.plain B.cipher C.public D.private A.plain B.cipher C.public D.private A.interpretation B.signatures C.encryption D.decryption A.plain B.cipher C.public D.private

本题的功能是监听键盘键的敲击，并显示在窗口中。 import javax,．swing．*； importjava．awt．*； ， import java．awt．event．*； public class java3 extends JFrame. extends KeyListener { private String linel=""line2="" private String line3="" private JTextArea textArea； public java3 { super("java3")； textArea=new JTextArea(10，15)； textArea．setText("Press any key on the key- board…")； textArea．setEnabled(false)； addKeyListener(this)； getContentPane．add(textArea)； setSize(350，100)； show； } public void keyPressed(KeyEvent e) { linel="Key pressed："+e．getKeyText(e． getKeyCode)； setLines2and3(e)； } public void keyReleased(KeyEvent e) { linel="Key released："+e．getKeyText(e． getKeyCode)； setLines2and3(e)： } public void keyTyped(KeyEvent e) { Linel="Key typed："+e．getKeychar； setLines2and3(e)； } private void setLines2and3(KeyEvent e) { line2="This key is"+(e．isActionKey?"" ："not")+"an action key"； String temp=e．getKeyModifiersText(e．get- Modifiers)； hne3="Modifier keys pressed："+(temp．e- quals("")?"none"：temp)； textArea．setText(linel+"＼n"+line2+"＼n" +line3+"＼n")； } public static void main(String args[]) { java3 app=new java3； addWindowListener(new Windowadapted { public void windowClosing(WindowEvent e) { System．exit(0)； } })； } }

A.FQDN

B.DNS name

C.Public key

D.Private key

In a public-key cryptosystem,(71)encrypted with the public key can only be deciphered with the private key from the same(72). Conversely,(71)encrypted with the private key can be decrypted only with the public key. Users can make their public keys(73)available or place them at a key distribution center or others to access. However, the private key must be(74)safe. In public-key systems there's no(75)to find a safe channel for communicating a shared secret key.

A．binarytext

B．hypertext

C．plaintext

D．supertext