How we might market a DBC’s (Digital Bearer Certificate) Unique/Cash-like features

Great explanation @Antifragile

And If a nasty man broke into your bank and stole that envelope could they spend the check or would they need my friends signature?

Wanting to know more, I googled “digital bearer certificates”. This topic comes out in the top 3 :smiley:
Let’s keep it there to get some exposure !


Very good question. What prevents me to sign multiple such envelopes with only one $100 bill? The only way how to prevent that is to do the signature online, in the bank. So the bank locks 100 USD on my bank account. This way it is online lock. If we want to prevent doublespend, the actual signature has to be done online too. I don’t know the details of implementation on safenetwork:) I am currious too.


We do this. So this is the process

  • You present bank (Safe) 100SNT as a dbc (Note1 say)
  • You sign it over to somebody else Note2 (another unknown key) Safe also signs this along with a SpentToken

When you then give the bank (Safe) the signed SpentToken then immediately Note1 is spent and Note2 is valid.

It’s that simple, so you can hold Note1 and Note2 but ONLY the Note who has
The parent spent token existing AND no spent token for itself is valid.

This wee trick ensures atomic swap from Note1 to Note2 i.e. if given Note2, you check “is it spent already” and is the parent (Note1) spent. That tells you everything. Also though if Note 2 contains the public key you control, then you know it’s not spent. So you only need to check Note1 is!.


How did I miss temporary.

Is this 100% certain as in you have another name in the bag?


Any name we publish before release will be snaffled by a simple copy cat, even blockchain or erc20 scam. They are too easy to create. The idea is we have some names and we will launch with one but hopefully snaffle it ourselves. So it will have to be simple unique and not able to be scammed as easily.


It’s ok. I’d be lying if I said I fully understood how they work. But I’m totally tantalised by the possibilities presented so far.


By a specific person or entity behind a SafeID or address, yes.

Yes, I believe so.

Yes, I believe this is true also. Although creating one might incur a small token cost, especially if you are putting some additional data in the DBC.

Yeah, there may well be a good case for different names for discreet use-cases. Especially if there is a fundamentally different purpose, i.e. one financial, one pure information, or contractual.

Voucher. Yes, this is an excellent and useful word. Banked!

One quality of DBCs that came up with the when we were talking about metaphors—after initially comparing them to cheques—is that they can be divided and sent to different people, and they can also be merged, or combined to make one larger one.

In this regard, they are not like cheques, or notes. In my mind they are much more akin to Gift Cards, in the way they work.

My wife always ends up getting these gift cards for a local chain store, and keeps them in her purse in a stack. She’ll use them online, or in several shops that accept them. She can go into one of those stores and check the balance on each (or scan the code to take a look on her phone) and often asks them to be combined into a single larger card. Or combines some, and gives one to me, and if I’ve signed it, only I can spend it. Sometimes I’ll take that card, and buy an Amazon gift card from the store, so I can spend it there!

Could those types of qualities also be applied to voucher?


This is nice and simple.

Yeah, it did feel nice and simple.

However, it might be too narrow, and fail to capture the qualities fully.

I.e. a DBC might never be on paper (I might just email it), and it doesn’t just represent a token. And it might get weird… “how many tokens does that paper token have on it?”

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I like the idea of framing it as just a physical SNT. Or that it is just an SNT, and SNT has the neat property of traversing between online and offline seamlessly.

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The way I’m thinking about it is, say from the Safe Network App, or my wallet app, I can happily send and receive token payments in the normal way, instantly online.

But, I have another option which is to create a gift card, or voucher, which can take them offline, or on the clearnet in a useful way.

It’s more than just ‘printing a token’ I think, because it can be assigned to just one individual, or have other things bundled in, or have other qualities that tokens by themselves don’t have.

Gift card seemed odd at first (the gift word anyway) but the way say amazon gift cards are used these days have very similar qualities, so should should be pretty understandable.

And these are only going to be as useful as they are understandable.

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For wrapping other items in a DBC, the simple and natural term of ‘certificate’ works really well. That’s the C in DBC afterall. Consider these example certificates from yesteryear:

You could have ‘Safe Certificates’ or ‘Salt Certificates’. (‘Salt’ being a generic term fir any altcoin or altoken on safe) This sounds very nice and articulate imo.


+ 1 for voucher. Amazon vouchers are a good analogy. They are a code that can be redeemed to an Amazon account and can be delivered by email, SMS or physical card, and are widely used and understood. Some people call electronic delivery e-vouchers to distinguish from the physical cards but that’s just a relic I think, like e-commerce.


I’m struggling to get the point of DBCs.

Why not just send the thing you want to the person you want to send it to?

I get the gift voucher concept, maybe even physical with a scratchable panel like Amazon gift cards etc, but the trust needed in the issuer & the requirement for a connection to validate balances makes it less than ideal for offline transactions / payments.

Can people highlight some real use cases? I can sense excitement around the DBC concept, and I want to understand why people are excited & see what possibilities DBCs could open up beyond what Safe network based transactions already allow.

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You don’t need to have an account on Safe to be able to receive a DBC.

A DBC can be passed around offline from one person to another physically (paper, USB stick etc).

A DBC can be signed over from one person to another offline.

I think all those are correct. They all have some limitation, but they are all examples that you can’t do just by sending from your online Safe to another SafeID


I have very little experience with gift cards. I didn’t know that you could do many of the things your wife does with them, like combine them for instance.

In my mind a voucher and a gift card is pretty much the same thing except that one is implied that it is a gift. So to me the same types of qualities that apply to gift card also apply to voucher.

A voucher is a bit wider though in my mind as I don’t feel a gift card is able to provide anything other than monetary value. But a voucher can be for more things, like a free ride in an amusement park, a free newspaper, or $20 off anything in a store, etc.


Thanks for these examples, though I don’t yet see how they could work.

E.g, how could a recipient know that the DBC being signed or passed over to them is valid for what the issuer says it is without a connection to the network?

If a DBC can be signed to another person, once that happens, a DBC on a USB stick / piece of paper would be invalid, but a recipient couldn’t know that without a connection. If there’s a connection, why not just transact online?

It seems to be a bit like a bitcoin paper wallet. Without access to the network, you can’t validate the balance, which means transacting offline requires significant trust.


I like voucher as well.

Is it possible to give those dbcs/vouchers an expiry date? Because that creates a lot of extra uses cases as well like temporary campaigns for shops or business

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If I’m going to pay for something I can just give away a DBC (digitally or physically) and it’s the other party’s responsibility to scan and receive it, rather than my responsibility to make sure I send it to the right place, which I think is nice.

I also like the idea of being able to generate DBCs and give them to friends to get them on the network easily.

I like being able to send tokens via snail mail if I want. Or give them as a physical gift to someone.

Or being able to “cash out” of the network and save the funds in a secure physical location if I’m suspecting I might get hacked or blackmailed for instance.

In general, I like how it brings the network into the physical realm.

Most people probably won’t use them unless the network gets huge, but they offer new use cases and a lot of flexibility to those who need or want it.


You can give an expiry date manually by saving the DBCs yourself and using them when the date comes around.