[H-2] Weak RNG Used in ChoosingRam::increaseValuesOfParticipants

Description:
The increaseValuesOfParticipants function in the ChoosingRam contract utilizes a weak source of randomness to determine the outcome of challenges between participants. This randomness is derived from block.timestamp, block.prevrandao, and msg.sender's address, all of which are publicly known values. Consequently, attackers can predict the outcome of the randomness generation, enabling them to always win challenges by calling the function at opportune moments.

Impact:
The lack of true randomness in this function allows malicious actors to manipulate the game mechanics, ensuring they can always emerge victorious in challenges. This undermines the fairness and integrity of the system, potentially discouraging honest participation.

Proof of Concept:
An attacker can deploy a contract similar to Attack::attackRandomness to exploit this weakness. By calculating the expected outcome of the randomness generation beforehand, the attacker can ensure victory whenever they participate in a challenge.

Tools Used:
Manual Review

Recommended Mitigation:
To address this vulnerability, it is recommended to use Chainlink's Verifiable Random Function (VRF) for generating truly random numbers. Chainlink VRF provides cryptographic proof of the randomness generated, ensuring that outcomes cannot be predicted or manipulated by any party involved.