Information Security Experiment 3: the use of PGP email encryption software

One 、 Purpose and requirements of the experiment

1. Familiar with public key cryptosystem , Understand the basic principle of certificate , Familiar with digital signature ;

2. Skillfully use PGP Basic operation , It can encrypt mail or transmission documents ;

Two 、 Experimental content

1 Create a private key and public key pair

  Use PGPtray Before , Need to use PGPkeys Generate a pair of keys , Including private key （ Only itself can access ） And a public key （ Can let exchange E-Mail People are free to use ）.

2 Exchange public keys with others

After creating the key pair , You can work with others PGP Users communicate . To use encrypted communication , Then they need their public key . And if they want to communicate with you, they also need your public key . A public key is a block of information , Publish public key （ You can put the public key on the key server , You can also paste the public key to a file or E-Mail Zhongfa wants to exchange with it E-Mail People who ）.

3 Verify the public key and make it valid

When getting someone's public key , Add it to the public key ring . First, determine the accuracy of the public key . When it is determined that this is a valid public key , You can sign to show that you think this key can be used safely . in addition , It can also give the owner of this public key a certain degree of trust .

4 Yes E -Mail Encrypt and digitally sign

When the key pair is generated and the key has been exchanged , You can do that. E–Mail Information and files are encrypted and digitally signed . If used E–Mail Application support plug_ins, Choose the appropriate option to encrypt ; If E–Mail The application does not support plug_ins, It can be E–Mail The information is sent to the clipboard and encrypted from there . If you also want to include some documents , It can be downloaded from Windows Exporer Encrypt and digitally sign on , And then hang up to E–Mail Send .

5 Yes E-Mail Decrypt and verify

       When someone sends you encrypted E–Mail when , Break down the content , At the same time, the additional signature is verified to confirm that the data is sent from the determined sender and has not been modified . If used E–Mail Application support plug_ins, Choose the appropriate option to encrypt ; If E–Mail The application does not support plug_ins, It can be E–Mail The information is sent to the clipboard for encryption , Copy the information to the clipboard and decrypt . If you also want to include some documents , It can be downloaded from Windows Exporer Decrypt on .

3、 ... and 、 Experimental environment

function Windows XP/2000 The computer of the operating system .

Four 、 Experimental steps and result analysis

1． Create a private key and public key pair

  1.1 Create user

 

  1.2 Generate private key pair and public key pair

Successfully created

 

2、 Exchange public keys with others

    2.1 Export public key

2.1 Send the public key to the other party of the communication

3 Verify the public key and make it valid

 

4、 Yes E -Mail Encrypt and digitally sign

    4.1 Encrypt file

Add key

 

    4.2 Digitally sign

 

    4.3 Send the encrypted file to the other party

5、 Yes E-Mail Decrypt and verify

    5.1 Decrypt the file after receiving it

    5.2 Decryption succeeded

 

• Summary of the experiment

Through this experiment , I am right. PGP With a deeper understanding .PGP Is a complete e-mail security software package , Include encryption 、 To identify 、 Electronic signature and compression technology .PGP It can provide information protection functions on independent computers , Make this security system more complete . It can be used to keep messages confidential to prevent unauthorized people from reading , It can also digitally sign the message so that the recipient can confirm the sender of the message , And be sure that the email has not been tampered with . It can provide a safe way of communication , There is no need for any confidential channel to pass the key in advance .