Use envelopes containing Litecoin private keys as cash

[wangxinxi]

Hard-to-fake and tamper-evident envelopes that contain Litecoin private keys can be used as cash and could enable easy adoption of Litecoins. Two versions are proposed: one is easy to use and cheap but less secure; the other is based on smart cards, which offers very high security and convenience and still remains cost effective.

1. EASY AND CHEAP VERSION
1.1 Description
On the surface of the envelope, there should be some textures like those on dollar notes to prevent it from being faked and the amount of Litecoins contained in the private keys to indicate the value it contains. The technology involved is called Security Printing [1]. The cost of printing one piece can be as low as 0.18 USD [2].

In most cases, you just need to check the appearance of the envelop like you check notes to make sure it is not faked. If you don't trust, you can simply open it and check the private keys.

1.2 Legal Status
Although purchasing from stores using these envelopes could cause legal issues, trading them between fiat money is no different from trading LTC directly and thus should have no problem. Interestingly, in many countries including the U.S, using this as currency can actually be legal [3, 4, 5].

1.3 Discussion
The advantages are: It is cheap. It works like cash and requires no mobile devices in most cases, so it is easy and convenient to use.
While dollars are used to be backed by gold but got changed later, this kind of Litecoin backed envelops are always backed the Litecoins contained inside. Moreover, the fact that those Litecoins can easily be redeemed gives it a big advantage compared with other private currencies like Digital gold currency [5].
Envelopes are just a metaphor. As long as we hide the private keys in a tamper evident way and we use security printing to prevent faked ones and we make them durable and easy to carry, we should be good.

2. ADVANCED BUT STILL COST EFFECTIVE VERSION
2.1 Description
For higher value ones containing like more than 10 Litecoins, we can create a more secure version using smart cards.
Instead of directly putting the private key of the Litecoins inside the envelope, we put inside the envelope a password and a NFC based smart card containing 1) the private key of the Litecoin, and 2) the private key of the issuing organization. We design the smart card in such a way that to read the private key of the Litecoins from the smart card, you will need the password contained in the envelope, and once the read is finished, the private key of the Litecoins will be automatically destroyed by the smart card immediately. So you cannot read the private key twice from the smart card.

Then, without opening it, we can use a mobile phone to verify that the envelope is indeed produced by the organization because it signs using the issuing organization's private key. Also, we can verify that the smart card indeed contains so much Litecoins because it signs using the private key of the Litecoins.
Also, we can see the envelope and the smart card need to be used together to retrieve the Litecoins. Without the envelope, you lack the password to retrieve the private key from the smart card. Without the smart card, the password inside the envelope is simply useless.

2.2 Discussion
The envelope including the password is required. There are two cases if we use only a smart card without the envelope.

• If any user can read the private key from the smart card, the smart card is basically useless. It's the same as printing out the private key on a paper and send it directly to another guy.
• If the private key in the smart card cannot be read by anybody and can only be used to sign, people then need to absolutely trust the issuing organization that it does not write the same private key into multiple smart cards.

Faking/duplicating the smart card is impossible as you don't have the private key of the organization. Opening the envelope and retrieve the private key of the Litecoins and then put the smart card into a faked envelope will not work as the private key has already been destroyed after you read it, so a mobile phone can verify that easily. And normal envelopes can be used. There is no need for money printing technologies.
For normal paper wallets or the one above, once you verify, they cannot be used anymore as you've already got the private keys. But it is good for small amounts.

Mobile wallets need network connection to send and receive Litecoins. It's good when both you and the receiver have network connection and wallets.

With this, the sender needs no network connection. And the receiver can verify within 2-3 seconds both the amount and the issuing organization if he/she has network connection. If there is no network connection, the receiver can still use a phone to verify whether it is from a trustworthy organization or not. If it is from a trustworthy one, and if the envelope seems OK, the receiver can pretty confidently accept it if the amount is within a few hundreds of dollars.

Many Chinese guys just want to buy Litecoins and store there and wait for the news about Litecoin price. It should be as easy as buying and storing gold. Right now, it's too difficult for them to download a mobile wallet and generate an address. And they have no idea about how to use a wallet securely. What if they lose their phones or reformat their hard disks? Making it physical is important. With this, they just need buy and lock them in their cabinets and forget about it.

Also, it provides absolute anonymity.

The cost of one smart card can be as low as 0.2 USD [6]. So the total cost should be less than 0.18 (security printing) + 0.2 (smart card) = 0.38 USD.

3. MAKE SURE NO ONE HAS EVER SEEN THE PRIVATE KEY
In Section 2, it appears that the issuing organization will have access to all private keys, which thus makes it the single point failure. Actually, it needs not be so. When the smart card is initialised, it randomly generates a password, which can be read out once and written down on the inside of the envelope, then it generates a pair of Litecoin public key and private key itself and keep the private key confidential until someone uses the password to retrieve it, upon which the private key gets destroyed as described in Section 2.

Therefore, during this setup process, no one has access to the Litecoin private key including the issuing organization, and thus this solves the Schrodinger's private key problem.

The organization can still keep the password and thus is able to read out the private key without tampering the envelope. But they need to have physical access to the smart card, which makes the whole process much harder. To make this process even harder, we can use very short range contactless smart cards, so a guy passing by is unlikely to get your private key. As always, you can use your smart phone to check whether it still contains a valid private key or not without opening the envelope or connecting to the Internet within seconds.

In this case, the issuing organization is needed only to make sure the security printing format is standardised and well accepted. It is not convenient to have too many kinds of envelopes.

4. COMPARISON WITH OPENDIME
https://opendime.com/ offers a USB based device that has less functionality but much higher cost. Basically, the USB device randomly generates a Bitcoin public/private key pair and the private key is kept secrete until you break the USB device physically. But because it is based on USB, it cannot work with phones conveniently. This is especially inconvenient when you are receiving it but have no computer to verify the Bitcoins inside it.

Please notice that the ideas above shall not be used commercially without a consensus. Opensource efforts are welcome. Thanks.

References
[1] https://en.wikipedia.org/wiki/Security_printing
[2] http://dgyongsheng.en.made-in-china.com/product-group/qehQugzjCRcB/Coupon-vouchers-security-printing-catalog-1.html
[3] https://en.wikipedia.org/wiki/Private_currency
[4] http://www.treehugger.com/culture/how-to-print-your-own-money-build-community-not-get-arrested-by-the-feds.html
[5] https://en.wikipedia.org/wiki/Digital_gold_currency
[6] https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=contactless+smart+card

[1715033001]

1715033001

[cryptohunter]

interesting ideas....nice to see something still going on with LTC

[110110101]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

[wangxinxi]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

Verification of the private key can be easily done by using a smart phone send a string to the smart card to sign. If the smart card produces a valid signature, and the signature's corresponding address contains so much Litecoins, then it is good. Because the communication is done through NFC, it is very convenient.

This is not divisible like cash. They can give you smaller ones as changes.

[The Sceptical Chymist]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

These will never be used at stores or anywhere else, so you don't have to worry about that.   OP probably hasn't noticed,  but we're moving away from a world of physical money, and trading paper wallets with a second-rate altcoin just isn't going to happen.

[wangxinxi]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

These will never be used at stores or anywhere else, so you don't have to worry about that.   OP probably hasn't noticed,  but we're moving away from a world of physical money, and trading paper wallets with a second-rate altcoin just isn't going to happen.

You don't know how popular LTC is in China.

[cryptohunter]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

Verification of the private key can be easily done by using a smart phone send a string to the smart card to sign. If the smart card produces a valid signature, and the signature's corresponding address contains so much Litecoins, then it is good. Because the communication is done through NFC, it is very convenient.

This is not divisible like cash. They can give you smaller ones as changes.

I like the idea. Sounds a very simple entry into crypto from fiat. Much easier than many hoops you have to jump through right now.

[kelsey]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

These will never be used at stores or anywhere else, so you don't have to worry about that.   OP probably hasn't noticed,  but we're moving away from a world of physical money, and trading paper wallets with a second-rate altcoin just isn't going to happen.

You don't know how popular LTC is in China.

hows is that a reply
LTC (and other cryptos) aren't at all popular in china. china a few years back was cash mostly, now on the street, just very recently tons of younger people are using phone payments, but i don't see cryptos in use at all.

[cryptohunter]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

These will never be used at stores or anywhere else, so you don't have to worry about that.   OP probably hasn't noticed,  but we're moving away from a world of physical money, and trading paper wallets with a second-rate altcoin just isn't going to happen.

You don't know how popular LTC is in China.

hows is that a reply
LTC (and other cryptos) aren't at all popular in china. china a few years back was cash mostly, now on the street, just very recently tons of younger people are using phone payments, but i don't see cryptos in use at all.

May be he just meant in comparison to other crypto? or compared to other countries using crypto?

In the US , UK or OZ most still have not really ever owned any BTC or any other crypto?

His idea still seems a very easy way of getting from fiat into crypto.

[kelsey]

Interesting idea, but I find it somewhat impractical.

When purchasing something at a store, how can the store owner know that the envelop actually contains a valid key and not some random lookalike address string? Manually verifying the private key seems like very time consuming task.

What about divisibility? Purchasing something with a predefined bill (envelope) makes it inconvenient to receive exchange. The merchant would have to have stacks and stacks with change envelops with tiny amounts of LTC.

This sounds like a nice way for giving away LTC for promotional donations, or other instances where the divisibility doesn't become an issue.

These will never be used at stores or anywhere else, so you don't have to worry about that.   OP probably hasn't noticed,  but we're moving away from a world of physical money, and trading paper wallets with a second-rate altcoin just isn't going to happen.

You don't know how popular LTC is in China.

hows is that a reply
LTC (and other cryptos) aren't at all popular in china. china a few years back was cash mostly, now on the street, just very recently tons of younger people are using phone payments, but i don't see cryptos in use at all.

May be he just meant in comparison to other crypto? or compared to other countries using crypto?

In the US , UK or OZ most still have not really ever owned any BTC or any other crypto?

His idea still seems a very easy way of getting from fiat into crypto.

i'm an aussie that works in china. in oz yeah i've seen token coffee shops etc that accept crypto, seem on the ground to be decreasing though, in china i've not ever noticed crypto in use on the street.

china online crypto exchanges are where the big turnovers in trading (thats pretty much a niche handful of people) but not any adoption whatsoever at street level in china.

we have to be atleast honest with ourselves where things are at.

the fastest way to get china using any crypto would be via phone apps, as thats a growing trend in china atm, they've mostly skipped over the card phase. been surprising between visit how quick adoption of cash to phone apps has occurred.

unless he's trying to copy the whole red envelope tradition here, with litecoin envelope  .

[European Central Bank]

i'm an aussie that works in china. in oz yeah i've seen token coffee shops etc that accept crypto, seem on the ground to be decreasing though, in china i've not ever noticed crypto in use on the street.

china online crypto exchanges are where the big turnovers in trading (thats pretty much a niche handful of people) but not any adoption whatsoever at street level in china.

we have to be atleast honest with ourselves where things are at.
 

that's because the Chinese government has expressly forbidden it. that was the cause of the 2013 fall. Chinese companies were starting to accept it as payment and the government stopped that. it's never gonna be used for that purpose in china publicly. if it does happen again then the government's gonna exterminate the bitcoin scene to the best of their ability.

[wangxinxi]

Litecoin is not even considered an altcoin in China. So it's not second-rating altcoin.

Red envelope could be a very good way between younger generations.

Those who are not very familiar with Internet can buy these as an investment like gold.

[spartak_t]

You don't know how popular LTC is in China.

That's not an argument. You do realize that there are like 450k unique Bitcoin addresses? If we assume (and that's a really optimistic suggestion) that the average Joe uses 2 BTC addresses, then we can conclude that around 225k people are using Bitcoin worldwide. That's nothing...   

[European Central Bank]

That's not an argument. You do realize that there are like 450k unique Bitcoin addresses? If we assume (and that's a really optimistic suggestion) that the average Joe uses 2 BTC addresses, then we can conclude that around 225k people are using Bitcoin worldwide. That's nothing...   

what's the definition of a unique address as opposed to a normal one? there are millions of those. and where are these couple of hundred thousand transactions per day coming from if there's so few users? I only transact 2-3 times per month.

[spartak_t]

That's not an argument. You do realize that there are like 450k unique Bitcoin addresses? If we assume (and that's a really optimistic suggestion) that the average Joe uses 2 BTC addresses, then we can conclude that around 225k people are using Bitcoin worldwide. That's nothing...   

what's the definition of a unique address as opposed to a normal one?

It means that 1 Bitcoin wallet can contain (for example) 10 addresses, and that 10 different addresses doesn't mean that 10 people are using Bitcoin.

[110110101]

--cut--

unless he's trying to copy the whole red envelope tradition here, with litecoin envelope  .

A nice analogy that I hadn't thought about. But again, this would rather be for gifting rather than actually payments between customer/merchants.
I understand OP wants to get LTC in the hands of users, but going through the paper route seems like a step back.

Anyway, even with faster confirmation times than BTC, LTC takes too long to ensure 1 confirmation for buying a mooncake at the store. Maybe the payments would have to be suited for situations where confirmations times are not as critical, like purchasing items for shipping online or where a wait for 2.5 minutes is acceptable.

[wangxinxi]

It can also be used as kind of commemorative coins. Perhaps we can make some for the 5th anniversary Litecoin?

[BitcoinHodler]

in my opinion there is one big fundamental problem with this idea:

by printing a cryptocurrency (private key on a paper) you are moving backwards in time. one of the innovations that cryptocurrencies has brought to us is making everything digital and also not needing a third party.

this idea is bringing both back to cryptocurrency scene!

instead of using a printed LTC private key use fiat it is a lot easier and a lot more secure and you don't have to worry about places to spend it.

also this is making things centralized again as there is a need for a central authority to print these private keys so everybody accepts it. you can't print it yourself and ask others to trust you.

[kelsey]

Litecoin is not even considered an altcoin in China. So it's not second-rating altcoin.

Red envelope could be a very good way between younger generations.

Those who are not very familiar with Internet can buy these as an investment like gold.

sorry from what i'm reading you seems to be very behind on china, perhaps limited to what you read about china/crypto on the internet.

have you seen how successful WeChat red envelops are becoming?

China now its used everywhere (surprised me how quickly its exploding), and even in Australia business are starting to accepting money via WeChat where chinese don't have to exchange can just pay straightly for CNY.........................................now this is the stuff that could make crypto viritually irrelevant  

average joe's don't want anon or over complication. they just want to be able to send money instantly p2p without fees etc keeping its simple and easy is the only way crypto should be heading.

[wangxinxi]

Litecoin is not even considered an altcoin in China. So it's not second-rating altcoin.

Red envelope could be a very good way between younger generations.

Those who are not very familiar with Internet can buy these as an investment like gold.

sorry from what i'm reading you seems to be very behind on china, perhaps limited to what you read about china/crypto on the internet.

have you seen how successful WeChat red envelops are becoming?

China now its used everywhere (surprised me how quickly its exploding), and even in Australia business are starting to accepting money via WeChat where chinese don't have to exchange can just pay straightly for CNY.........................................now this is the stuff that could make crypto viritually irrelevant  

average joe's don't want anon or over complication. they just want to be able to send money instantly p2p without fees etc keeping its simple and easy is the only way crypto should be heading.

I still go back to China sometimes. I know how convenient it is to use WeChat or Alipay. But cash is still a very important part of our daily lives. Do you know that in China there is still a big proportion of people that don't know how to use Internet? They don't even know how to use a bank ATM card. They have no idea of what username and password are. How do you expect them to understand something like Litecoin if it is not in a physical form? Even many of my college classmates in computer science major think it's complicated to use. Maintaining a wallet for normal users is a big headache. What if they lose their phone or wipe their hard disk? Do you expect everyone to know how to backup a wallet properly? How many Bitcoins were reported to be lost because of backup issues?

You can also read this article https://www.reddit.com/r/litecoin/comments/5518gc/bringing_litecoin_to_the_masses/ written by a guy who knows the situation in South America.

Yes, all these will be improved in the future. But this is the situation right now. Whether you like it or not, you just cannot expect everyone is as smart and well educated as you. And physical Litecoin is definitely suitable for this situation. Are we going backwards in time? No, we are just trying to satisfy users' need.

Also, given the low cost of it, what can be wrong of doing it?

Also, it's a better replacement for OpenDime.