Suppose one generates an account with the following procedure:
Flip a coin 256 times;
On a paper, write each heads as 1 and each tails as 0;
Convert the 256-bit string to hex by mapping each 4-bit sequence to a char from
Save that 64-character hex string to a file (say,
echo 'ABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCDABCD' > priv.txt);
Import that private key using
geth account import;
Remove the file:
Store the private key in a safe place, offline.
Is to know if this procedure is safe or if is there any potential issue with it.