You can buy a piece of 100x50x3 mm 316 stainless steel (thats 4"x2"x1/8" in freedom units) for around $5.
Engraving it is a simple matter of using a $10 automatic center punch and write the password out in dot punched letters.
If necessary, cut plate in N pieces with a hack saw, distribute among N people.
I always mark bicycles this way, dot punch my last name underneath the bottom bracket shell.
You can buy a piece of 100x50x3 mm 316 stainless steel (thats 4"x2"x1/8" in freedom units) for around $5.
Engraving it is a simple matter of using a $10 automatic center punch and write the password out in dot punched letters.
If necessary, cut plate in N pieces with a hack saw, distribute among N people.
I always mark bicycles this way, dot punch my last name underneath the bottom bracket shell.