What is the typical key size of a strong encryption system

Write 500 words that respond to the following questions:  

• What is the typical key size of a strong encryption system used on the Web today? Explain your answer with examples.
• Explain the roles of the random numbers in the use of encryption for the security of web applications.
• Provide at least two references to support your initial post.
•  
• Be in APA format including your references.
• Be 500 words long (not including title and references).
• Do not re-state the questions.
• Include two sources (i.e. two references).
• Respond to at least two of your fellow classmates.