  The need of totally secure online auction has led to the invention of many
auction protocols. But as new attacks are developed, auction protocols also
require corresponding strengthening. We analyze the auction protocol based on
the well-known mathematical public-key knapsack problem for the design of
asymmetric public-key knapsack trapdoor cryptosystem. Even though the knapsack
system is not cryptographically secure, it can be used in certain auction
situations. We describe the limitations of the protocol like detecting and
solving the tie between bidders, malicious behavior of participants and also
selection of price set by the seller and offer solutions.
