randomness

randomness

tl; dr

post-merge notes

• BLOCKHASH opcode will still be available, but given that it will no longer be forged through the proof of work hashing process, the pseudorandomness provided by this opcode will be much weaker.
• DIFFICULTY is renamed to PREVRANDAO, and return the output of the randomness beacon provided by the beacon chain. It's stronger than BLOCKHASH but still biasable.

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cool resources

• randao target slot attack analysis, by jtapolcai (2025)
• ethereum randomness
• randao github
• exploring the randao game in pos ethereum
• exploring cryptokitties midwives (giveBirth() as an example of flawed economic incentive and randomization)