spacing: 20 80
fontsize: 20 
def: b rect bloc        160 50 none red
def: t rect transaction 50 50 blue yellow
def: T transaction.s transaction 150 150 blue yellow
def: n rect nonce	       80 50 green
def: h rect hash        120 50 red
def: p preuve.s proof     50  50 yellow
def: s rect sign        150 50 black
def: f filler filler    20  50 none
def: F filler filler    0 0 none
def: _ line ???         80 50 red
def: D dots.s dots      80 150 blue
