README.MD

Run Main.java, which will run 10 times with random blood types and then use d-HE to do the compatibility and then check if the result was correct.
Running the tests might take a while and the number of tests can be changed in Main.java

For choosing this subset we do the following:
1. Choose a random value y which is going to be the length of S
2. Then we shuffle the list of public keys (y_1,...,y_n) randomly 
 3. Then pick the first y elements in the shuffled list this is then our subset S

Security of this in terms of the encryption, since we choose the size of S randomly
and the choice of yi's is uniformly random since we shuffle the list of yi's randomly.
Then an adversary wouldn't be able to differentiate the sum of the yi's with a random
value added to the message.