Generating a private key using dice
Can a bitcoin mnemonic or private key be diced – completely without a computer involved?
Yes, you can generate a 256-bit number randomly and use that as a private key. It must be in the range 1 to 115792089237316195423570985008687907852837564279074904382605163141518161494336.
See but note the warnings on that page
Generating a “mnemonic” phrase from a private key.
you could go from private key to mnemonic, right?
Not if you follow Bitcoin Improvement Proposal 39,
- First, an initial entropy of ENT bits is generated.
- A checksum is generated by taking the first ENT / 32 bits of its SHA256 hash. This checksum is appended to the end of the initial entropy.
- Next, these concatenated bits are split into groups of 11 bits, each encoding a number from 0-2047, serving as an index into a wordlist.
- Finally, we convert these numbers into words and use the joined words as a mnemonic sentence.
It is the checksum in step 2 that means the last word cannot be chosen at random.
We have
Random number R -> R + Checksum(R) -> array of 11-bit elements -> indexed words
then
word list -> ... -> master private key
So far as I know, that process is not reversible. This means you can’t generate a BIP-39 “mnemonic” word list from a private key.
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