title_body: Why are Cardano transaction fees so high? It's obviously a lot less than Ethereum's, but 0.17 ADA isn't insignificant. What are the main reasons it can't be 0.00017 ADA?
upvoted_answer: There are a important reason that explain why the fees can't be 0.00017 ADA,the prevention of DDoS attacks
  The minimal fees for a transaction are calculated according to the formula
  a + (b × size),
  where 'a' and 'b' are constants and 'size' is the size of the transaction in Bytes. At the moment, the constants 'a' and 'b' have the values
  a = 0.155381 ADA,
  b = 0.000043946 ADA/Byte.
  This means that each transaction costs at least 0.155381 ADA, with an additional cost of 0.000043946 ADA per Byte of transaction size. For example, a transaction of size 200 Byte (a fairly typical size) costs
  0.155381 ADA + 0.000043946 ADA/Byte × 200 Byte = 0.1641702 ADA.
  Why did we pick this particular formula? The reason for having parameter 'a' is the prevention of DDoS attacks mentioned above: even a very small dummy transaction should cost enough to hurt an attacker who tries to generate many thousands of them. Parameter 'b' has been introduced to reflect actual costs: storing larger transactions needs more computer memory than storing smaller transactions, so larger transactions should be more expensive than smaller ones.
  Therefore, it is better to perform transactions of a large number of Ada than to perform multiple transactions of a lower number of Ada.