I want to generate my own private key with dice and/or other very entropic phenomenon.
Bitcoin blockchain itself is a great source of entropy. Last digit of each block is itself random. There is a dedicated thread discussing this phenomenon -
https://bitcointalk.org/index.php?topic=1493510.0Yes but since it's public and a lot of people know bitcoin is it secure to use it ? Some hacker can "datamining" the hash of each blocks to steal cryptos. The same way they did datamining on brain wallet, a lot of people wich passphrase was a poem get hacked because the passphrase was hashed to a private key so hacker can attack all brain wallet in the same time (it's different from a bruteforce because bruteforce is agains a sample of encrypted data).