Two Payment Protocols for Content Distribution System

• Main Authors: Chi Chang, 張霽
• Other Authors: Sung-Ming Yen
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/10343743835780614141

碩士 === 國立中央大學 === 資訊工程研究所 === 98 === With the widespread use of the internet, there are more and more e-commerce systems being developed. Digital contents such as audio, video, or articles can be distributed easily, and many digital contents now can be sold on the internet. Content distribution system (CDS) is a system where the original authors can upload their contents onto a distributor and the distributor will spread the contents. In fact, some authors may wish to sell their contents, so they may ask the distributor to help them sell their works. For example, a music studio can upload their music onto iTunes and customers can buy music from iTunes. The original author can earn royalty fees and the distributor can earn distribution fees. Most existing payment protocols in CDS need the on-line involvement of a trusted broker. Due to the frequent involvement of the trusted broker, it will reduce the efficiency of the system, and the computational capability of the broker may become the bottleneck of the system. In our works, we present two off-line payment protocols in CDS. The first proposed payment protocol will focuse on the fairness issues. A customer (buyer) may not trust the distributor that the distributor will honestly give him the content after he signed a valid signature as a check. On the other hand, the distributor may not trust the customer either. We proposed a payment protocol with fair ciphertext/signature exchange procedure, which garantees that both parties either recieves or not revieve the intended things. We combine the proxy re-encryption scheme and concurrent signature into a fair ciphertext/signature exchange procedure. The second proposed payment protocol is a micropayment protocol that will focuse on the efficiency issues. When the price of the content is extremely low, the distributor may deal with a lot of transactions at the same time. The computational cost of bank and distributor should be low enough such that the system can work correctly. We use aggregate signature, chameleon hash, and payword to construct a micropayment protocol in which the verification of signatures is delayed and in batch. Although the verification of signatures is delayed, the second proposed protocol contains a dispute handling procedure, which guarantees that even if the disputes happen, the broker can still handle it.