Diffie-Hellman Key Exchange calculations program

DHKE.rb

class Diffie

    def self.publicKey(base, modPrime, aSecret)
        
#        puts "Enter your shared prime (g): "
#        base = Integer(gets.chomp)
#        puts "Enter your second prime (p): "
#        modPrime = Integer(gets.chomp)
#        puts "Enter your secret prime (a): "
#        aSecret = Integer(gets.chomp)
        
        publicKey = base ** aSecret % modPrime
            print "Share this with your contact: " + publicKey.to_s
    end
    
    def self.shareSecret(publicKey, modPrime, aSecret)
        
#        puts "Enter the shared secret from your contact (A): "
#        publicKey = Integer(gets.chomp)
#        puts "Enter your second prime (p) :"
#        modPrime = Integer(get.chomp)
#        puts "Enter your secret prime (a): "
#        aSecret = Integer(gets.chomp)
        
        shareSecret = publicKey ** aSecret % modPrime
            print "Compare this with your contact: " + shareSecret.to_s
    end

end

puts "Are you computing the public key or the shared secret?"
answer = gets.chomp

if answer.downcase.eql? "public key" then
    puts "Enter your shared prime (g): "
    base = Integer(gets.chomp)
    puts "Enter your second prime (p): "
    modPrime = Integer(gets.chomp)
    puts "Enter your secret prime (a): "
    aSecret = Integer(gets.chomp)

    puts "Share this with your contact: " + Diffie.publicKey(base, modPrime, aSecret).to_s + "\n"
    
elsif answer.downcase.eql? "shared secret" then
    puts "Enter the shared secret from your contact (A): "
    publicKey = Integer(gets.chomp)
    puts "Enter your second prime (p) :"
    modPrime = Integer(gets.chomp)
    puts "Enter your secret prime (a): "
    aSecret = Integer(gets.chomp)
    
    puts "Compare this with your contact: " + Diffie.shareSecret(publicKey, modPrime, aSecret).to_s + "\n"

else
    puts "Goodbye."

end

ruby-out.txt

$ ruby DHKE.rb
Are you computing the public key or the shared secret?
public key
Enter your shared prime (g): 
7
Enter your second prime (p): 
5
Enter your secret prime (a): 
2
Share this with your contact: 4Share this with your contact: