The main features of a hashing algorithm is that they are a one way function – or in other words you can get the output from the input but you can’t get the input from the output – just like elliptic curve cryptography where you can’t get the private key from the public key. In this case:
keccak256(...) returns (bytes32)
Compute the Ethereum-SHA-3 (Keccak-256) hash of the (tightly packed)
arguments
In this case the two points.
Basically you're generating a hash from the points you specify and as stated above hash functions are one way functions. So you wont be able to get the points from the hash.
If you want to learn more about hash fucntions
visit:
https://searchsqlserver.techtarget.com/definition/hashing
or about keccak256(...)
visit the Ethereum documentation:
https://solidity.readthedocs.io/en/v0.4.21/units-and-global-variables.html