IText PDF Won't Permit Encryption?

I am attempting to encrypt the file that is generated by Itext:

def download   str = Rjb::import("java.lang.String");   pw = Rjb::import("com.lowagie.text.pdf.PdfWriter")   d = Rjb::import("com.lowagie.text.Document")   ba = Rjb::import("java.io.ByteArrayOutputStream")   b = ba.new()   p = Rjb::import("com.lowagie.text.Paragraph")   document = d.new()   s = str.new("user")   pwd = s.getBytes()   writer = pw.getInstance(document, b)   writer.setEncryption(pwd, pwd,2052,1);   document.open()   document.add(p.new("Hello!!!"))   document.close()   bytes = b.toByteArray()   send_data(bytes, {:filename => "Letters For Printing.pdf", :type => "application/pdf"})   end

Every time I call the above method I get the error :

NoClassDefFoundError in LettersController#download

org/bouncycastle/asn1/ASN1OctetString

RAILS_ROOT: C:/ruby/letter4sure Application Trace | Framework Trace | Full Trace

app/controllers/letters_controller.rb:184:in `method_missing' app/controllers/letters_controller.rb:184:in `download' -e:2:in `load' -e:2

c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `send' c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require' script/server:3 -e:2:in `load' -e:2

Request

Parameters:

{"id"=>"77"}

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