Virtual Sheet Music transmits credit/debit card or check information through PayPal® Payflow gateway service (formerly managed by VeriSign®) using HTTPS (Secure Hypertext Transfer Protocol), developed by Netscape and now built into Microsoft and Netscape browsers. This protocol uses the open Secure Socket Layer (SSL) under the HTTP application layer to encrypt and decrypt user page requests, as well as the pages that are returned by the web server. Today, SSL uses a 1024-bit RSA key length for the encryption algorithm. This system is widely considered to provide more than adequate security for commercial purposes, and is the de facto standard for transactional websites. Our SSL certificate is assured by VeriSign Inc. authority.