The problems to be solved by the below described approach are: increasing of transaction speed and lowering the block chain size.
    
With the proposed type of cryptocurrency there are two types of transactions.

First is the usual one that gets registered in the block chain unconditionally.  
The other type is somewhat reminiscent of a lottery ticket (LT). With exception of some additional requirements an LT inherits the properties of a usual transaction.

An LT type transaction gets into the block chain with some set probability that is written in an LT itself. The lottery is performed by the miner based on the found "pretty" hash. 

An LT can only be registered into the block chain block that follows
a block specified in the LT. 

The miner searches the hash of the previous (not the current) block as the full set of tickets that passed the lottery is not ready yet.

The LTs to be registered into the block chain have to satisfy a function with a "pretty" hash as a parameter. 

The "pretty" hash of the previous block gets registered into the current along with the transactions. 

Later the current block is signed with the usual electronic signature corresponding to the miner address.
    
I think that to exclude the possibility for the miner to create a modification of the current block, some additional requirements have to be added to the 
"prettiness" of the current block hash. This will make it not easy to modify the current block.

Any other possible reasons of these payments not passing are added to the base probability of LT and can be accounted for when
mathematical expectation of transaction passing is calculated. 

The LT commission is presented as a separate transaction that includes
the sum and the link to the original LT. It is signed with the receiver address. This allows to increase the commission in case of a competitive translations
appearance.

The currency usage is with small electronic services such as:
cloud computing, paid databases, file and currency selling, paid email ans so on. The electronic shop in this case is an interpreter of the client commands with LT as a parameter.

One of the cloud computing usages can be a mining pool. In this case each pool can have their own coin client without accounts for mining helpers. 
The payments are instantly done with LT. 

An interesting innovation can be an additional method of block signing. Beside the proof of work (PoW) there will also be proof of lottery (PoL). The PoL is performed LT caught in the block chain. The PoL has to include PoStake but the parameter of PoStake will be a commission with miners owning LTs. 

For an LT to be "owned" by the miner the sender or receiver address have to match with the miner's address. 

The right to mine PoLottery is given to a miner when their tickets are present in the two last blocks of the block chain.

The parameter of the PoStake will be the minimum of maximum of the commission of the owned tickets in the last two blocks. This rule is needed because the miner has no problem adding to the block chain a ticket to himself with a huge commission. 

Each algorithm (PoW and PoL) has its own difficulty. A change of a difficulty is only performed for one of the algorithms per time. The choice of the algorithm to change difficulty for is preformed depending on relative usage of the algorithms in the block chain from the last time difficulty was changed. 

The difficulty should be set such that the PoL signed blocks happen more often then PoW blocks. This is because PoL supports the business.

Therefore before determining the relation between PoW and PoL usage the PoW is multiplied by some value. A "lucky" combination of LT gives a miner temporary
privilege which in turn temporarily increases the mining helpers reward. In this case an alerting / messaging system can be used so that helpers are aware of what's going on and can be invited to cooperate.

 	My dream is to create a commercial support for the open development. http://fpauk.narod.ru/statia3-1.txt. The LotteryCoin can solve the problem of launching of the evolutionary software development with help of the independent developers. It will also make the intellectual work of wide variety of people masses more demanded.