I want to print and distribute several One Time Passwords (OTPs) that can't be easily disclosed to a 3rd party in transit. (think the physical version of a TLS session for private secrets)
To me that means I need a non-electronic list of passwords that are protected by a physical means such as a secure envelope, or silver coating.
- What are my options as far as printing and distributing these OTPs to end users?
One of the first options that come to mind is to have a company like BABN/Oberthur Technolgies print this with a scratch off similar to how they print lottery tickets, however they are only interested in high volume distributions.
Based on my experience in the lottery ticket industry, there is a lot of technology that goes into the silver coating, and often there are several layers of ink and patterns laid on top of each other. And even with this, some ink layering techniques are better than others.
- What "scratch off" technology is secure enough for an OTP password? What should I avoid?
As an alternative to the silver coating, perhaps a perforated envelope could be used. ADP is well known for their secure printing facilities (for checks) that make it difficult to impossible to view the contents of one of their tamper evident envelopes. Again, they aren't in the business of distributing OTP tokens to end users in small volumes.
- Are there any in-house or outsourced opportunities available?
- What other physical features should I look at w.r.t. a OTP password list (waterproof, etc)