Lab 11.1: Running an RSA Cipher Demonstration

Time: 15 minutes

Description:  The steps for encryption using RSA can be illustrated in a Java applet on a Web site. In this lab, you observe how RSA encrypts and decrypts.  Note: It is recommended that you review the section earlier in this chapter in the text regarding the steps in the RSA function.

  1. Open Internet Explorer and go to
    It is not unusual for Web sites to change the location where files are stored. If the preceding URL no longer functions, then open a search engine and search for ôRSA Cipher Demonstration."  Note: Be aware that some URLs are case-sensitive, use upper and lower case where indicated.

  2. Change the RSA key bits size to 256.

  3. Click the GenerateKey button to generate the prime factor p and prime factor q numbers. These are the prime numbers that will be used.

  4. Enter Today the sun is shining! in the Plaintext box.

  5. Click the Encrypt button to encrypt this phrase using RSA.

  6. Delete the text Today the sun is shining! in the Plaintext message box.

  7. Click the Decrypt button and notice that the message in the Plaintext box reappears.

  8. Click the Page menu and click Save as.

  9. Type C:\temp\11-1.mht in the file name box and click Save.

  10. Close the window.

  11. Close the lab by clicking the Close Lab icon on the lab toolbar.