6 ms·

One thing I really love that Japan got right was the creation of e-money systems that are anonymous (you can get a Suica for 20,000 yen without any registration

by Shank 1y ago

One thing I really love that Japan got right was the creation of e-money systems that are anonymous (you can get a Suica for 20,000 yen without any registration information), work offline (you don't need network at-payment, nor does the terminal), and are easily accessible (you can get them at any train station, you can charge them at any ATM or convenience store with cash). In contrast, a debit/credit card usually requires a lot more pain to get onboarded with. The closest thing is probably those silly visa prepaid cards you can buy, but they require a little work to use regularly.

csinode 1y ago
> work offline (you don't need network at-payment, nor does the terminal) Surely this is massively vulnerable to double spend attacks?
- andreareina 1y ago
  It's been in widespread use for a while at this point so in practice probably not. I imagine the authentication keys to present as a card are very tightly controlled and not just anyone can become a provider.
- Shank 1y ago
  > Surely this is massively vulnerable to double spend attacks? FeliCa uses mutual authentication with eventual bookkeeping and sync. I believe that there are some theoretical attacks on older cards but the terminals are regularly synchronized and get a ban list. In-practice, you’ll also be reported to the police, probably.
- lmm 1y ago
  Not really - what's the attack? You could maybe somehow clone a card with a balance on it and spend that balance twice, if you can figure out that a particular terminal is offline (or have a way to take it offline), but how do you turn that into an attack that you can scale enough to cover the fixed costs? You're not getting your own terminal without a contract and due diligence on your company, so you can't really pull off an attack that needs to control both sides.
- rtpg 1y ago
  My understanding here is that there's less risk of double spends here because of the extreme difficulty of cloning the smartcards involved. So to execute the double spend you would have to find an authorized card provider, convince them to load and sign your double spend-capable program onto the smartcard (with their signature!), and then be found out within a week when reconciliation is off. So doing a double spend will be found out, and not only will you be on a bunch of cameras doing the thing, whoever made your card will also have been compromised. I think that in practice the "eventual" reconciliation is fairly quick nowadays. Just that the offline spend can happen quickly, and then the packet gets sent over the wire maybe a minute later rather than before the spend is approved.
  - beeflet 1y ago
    Or you can extract the secrets from a smartcard using a variety of side-channels. But the juice is rarely worth the squeeze.
    - rtpg 1y ago
      Maybe you can, but I had the impression that it would be quite difficult given physically unclonable function-y stuff. Handwave-y and I have no clue if Suica-style payments use it but that was my impression.
  - Shank 1y ago
    > I think that in practice the "eventual" reconciliation is fairly quick nowadays. Just that the offline spend can happen quickly, and then the packet gets sent over the wire maybe a minute later rather than before the spend is approved. This is definitely the case, and it's also "relatively instant" in the happy path. There are cases like vending machines, or during system outages where the reconciliation happens much later, but those instances are definitely becoming rarer!
  - account42 1y ago
    It's really not that big of an issue when the spends are reasonable sized (e.g. public transport). You don't need to prevent literally all fraud, just enough that it becomes an acceptable cost of doing business. Fielding customer complaints because they couldn't ride due to an offline reader isn't free either.
- beeflet 1y ago
  Not nessisarially because it can take advantage of TEEs in smart cards
- raincole 1y ago
  In Taiwan, there is a similar system called EasyCard. That works offline. ...And as you expect it is vulnerable to double spend attacks. Hilariously the vulnerability was revealed in 2014 and nothing has been done to mitigate it. Yes, you can double spend in Taiwan today if you don't mind risking jail time. From my (rudimentary) understanding of CAP, there is no prefect solution to this. I wonder how Japan handles it.
  - account42 1y ago
    You can also "double spend" cash with fake bills. Zero fraud is never a reasonable design goal. Much easier than double spending would be to use a student or other reduced fare card.
mappu 1y ago
I think a lot of the motivations are AML. Suica has a low maximum balance, that probably restricts the nefarious use cases.
- Shank 1y ago
  I would personally argue that 20,000 yen is not a low maximum balance for day-to-day purchases like food, because you can recharge so easily. Before Suica (and a bit concurrently), JNR and later JR issued "orange cards" that included both high value formats and lower value formats. The "high value" cards were 5,000 yen and 10,000 yen respectively, so the new maximum is 2x the previous "high value" orange cards that they abolished. The real win with e-money is not getting change, in my opinion. Carrying 20,000 yen in cash is easy when it's 2x 10,000 notes, but when it's a mix including coins, it's a pain.
  - CapricornNoble 1y ago
    >Carrying 20,000 yen in cash is easy when it's 2x 10,000 notes, but when it's a mix including coins, it's a pain. Carry a coinpurse. I use an old faux-suede Samsung camera pouch.[1] Plus it's fun when someone is running an errand for you, like getting you a snack from the konbini across the street, and you plop your coinpurse on the desk with a thud, then pour out a handful of 500-yen coins and say "this should cover it", like a feudal lord. [1] kinda like this: https://www.amazon.ie/DFVmobile-Samsung-Galaxy-Camera-Closure/dp/B075K8TJR7 https://www.amazon.ie/DFVmobile-Samsung-Galaxy-Camera-Closur...
    - charcircuit 1y ago
      Why have a whole purse when it is already built into your phone which you already are carrying around anyways.
      - account42 1y ago
        Because my coin purse isn't going to randomly decide that it doesn't like the transaction.
cosmotic 1y ago
Meanwhile, there's no apparent way to pay for a train using an American android phone (or at least I couldn't figure it out last year). One of the two apps refused to install on non-japanese phones, the other installed but refused to run. Had to pay with cash and it was a huge pain. Half the time I inexplicably had to do a fare adjustment, a hugely embarrassing moment blocking the turnstile, especially considering the culture there.
- cosmic_cheese 1y ago
  That’s thanks to Android phone manufacturers, which don’t want to pay for a global license for the NFC tech involved. Apple on the other hand does pay for a global license and so iPhones and Apple Watches from anywhere work perfectly with Japanese cash card terminals. I use a digital Suica on my US iPhone during my visits. Supposedly Pixels have the requisite hardware, but Google software locks the functionality to Japan. Some have been able to hack their Pixels to force it on but from what I’ve gathered it’s flaky when you do that.
  - seabass-labrax 1y ago
    Why should they pay for a licence? Once a technology reaches such ubiquity, there's a strong case for it being part of the technical infrastructure of that society. To me, that means that governments have a responsibility to ensure that the technology is widely available, and arbitrarily locking it behind commercial licences does not help achieve that. To the extent that patents and licensing provide an incentive to develop such technology, it's beholden on governments to foot the R&D bill in some other way.
    - cosmic_cheese 1y ago
      I see your point, but at the same time fracturing product lines into a million micro-SKUs also isn’t great and should be discouraged.
    - lmz 1y ago
      Using this sort of logic Windows would be mandatory and paid for by the government on all your 90s, 2000s laptops.
mapt 1y ago
Those prepaid visa cards don't actually exist, I think they were killed by AML/KYC. Instead, they appear to be "prepaid visa gift cards" accepted at less than a hundred large chains.
- Larrikin 1y ago
  This is wrong. The visa gift cards work pretty much everywhere, unless they are specifically disabled by the establishment. They do show as a gift card but all the POS systems are perfectly capable of splitting the payment now. I've only seen them disabled at small restaurants that have dealt with scam charge backs and sites like Raise that deal in gift cards and gift card scams as part of their business. Usually they simply aren't worth it because of the activation fee. It's always more than the highest paying credit card cash back. However sometimes stores, run sales where they waive the activation fee, but there's always a limit.
m463 1y ago
to me suica seemed limited (for a traveler). you could get one and charge it up with a credit card, but I don't think you could recharge it that way. You could also not get multiple ones. I believe there is a less limited suica card you can get (not a traveler), but I think you need a japanese address.
- Shank 1y ago
  > I believe there is a less limited suica card you can get (not a traveler), but I think you need a japanese address. You don’t need a Japanese address. Simply visit any Suica vending machine, change the language to English, and purchase anonymous Suica. There are various preloaded options you can purchase, but typically you cannot recharge e-money via cash.
  - m463 1y ago
    the vending machine card was the red one, right? I though there was a (blue?) one that japanese citizens could get, sent to their address.
    - veeti 1y ago
      The red is a 30 day card for tourists. The green is valid for many years. You can get both anonymously, but there was a chip shortage a while back which meant only the red cards were widely available.
    - Shank 1y ago
      > I though there was a (blue?) one that japanese citizens could get, sent to their address. No, there are no citizen specific IC cards unless you want extremely esoteric ones, like for senior citizens or children. All of the major nationwide mutual use transportation IC cards are freely available at the stations their operators carry. That's anything in the red box on this chart: https://en.wikipedia.org/wiki/Suica#/media/File:ICCard_Connection_en.svg https://en.wikipedia.org/wiki/Suica#/media/File:ICCard_Conne....
    - socalgal2 1y ago
lisbbb 1y ago
But Japanese people largely still use cash, don't they?
- trenchpilgrim 1y ago
  This isn't as true as it used to be. Mobile pay and IC-type cards have risen in popularity, and if you have a credit card, it's accepted in many places.
- lofties 1y ago
  This is no longer true. With the advance of "cashless" systems that were heavily pushed and promoted by the government, cash payments have dropped significantly![0] Cashless payments now sit near 50%, up from 16% 10 years ago. [0]https://www.meti.go.jp/english/press/2025/0331_001.html https://www.meti.go.jp/english/press/2025/0331_001.html
  - rendaw 1y ago
    But not the anonymous, offline, accessible payment systems this thread is about. The online, ad infested phone-app-only, less accessible "cashless" systems like paypay. Even today the only place you can buy food with your pasmo/suica card is at the convenience store. Why is that?
- Gathering6678 1y ago
  From my experience, apart from small restaurants and yatais (basically food carts), as well as local buses in small towns, you could get by using a credit card / Suica perfectly fine.
ekianjo 1y ago
Suica is far from being accepted everywhere. in Japan cash is your best bet.
wakawaka28 1y ago
Keep in mind that "anonymous" money systems are not untrackable. You need to have killer OpSec to actually have an anonymous digital wallet even if it is technically possible. I'd rather not deal with that extreme discipline. Cash does the job just fine, at least for in-person transactions.

by Shank 1y ago

csinode 1y ago

> work offline (you don't need network at-payment, nor does the terminal) Surely this is massively vulnerable to double spend attacks?

andreareina 1y ago
It's been in widespread use for a while at this point so in practice probably not. I imagine the authentication keys to present as a card are very tightly controlled and not just anyone can become a provider.
Shank 1y ago
> Surely this is massively vulnerable to double spend attacks? FeliCa uses mutual authentication with eventual bookkeeping and sync. I believe that there are some theoretical attacks on older cards but the terminals are regularly synchronized and get a ban list. In-practice, you’ll also be reported to the police, probably.
lmm 1y ago
Not really - what's the attack? You could maybe somehow clone a card with a balance on it and spend that balance twice, if you can figure out that a particular terminal is offline (or have a way to take it offline), but how do you turn that into an attack that you can scale enough to cover the fixed costs? You're not getting your own terminal without a contract and due diligence on your company, so you can't really pull off an attack that needs to control both sides.
rtpg 1y ago
My understanding here is that there's less risk of double spends here because of the extreme difficulty of cloning the smartcards involved. So to execute the double spend you would have to find an authorized card provider, convince them to load and sign your double spend-capable program onto the smartcard (with their signature!), and then be found out within a week when reconciliation is off. So doing a double spend will be found out, and not only will you be on a bunch of cameras doing the thing, whoever made your card will also have been compromised. I think that in practice the "eventual" reconciliation is fairly quick nowadays. Just that the offline spend can happen quickly, and then the packet gets sent over the wire maybe a minute later rather than before the spend is approved.
- beeflet 1y ago
  Or you can extract the secrets from a smartcard using a variety of side-channels. But the juice is rarely worth the squeeze.
  - rtpg 1y ago
    Maybe you can, but I had the impression that it would be quite difficult given physically unclonable function-y stuff. Handwave-y and I have no clue if Suica-style payments use it but that was my impression.
- Shank 1y ago
  > I think that in practice the "eventual" reconciliation is fairly quick nowadays. Just that the offline spend can happen quickly, and then the packet gets sent over the wire maybe a minute later rather than before the spend is approved. This is definitely the case, and it's also "relatively instant" in the happy path. There are cases like vending machines, or during system outages where the reconciliation happens much later, but those instances are definitely becoming rarer!
- account42 1y ago
  It's really not that big of an issue when the spends are reasonable sized (e.g. public transport). You don't need to prevent literally all fraud, just enough that it becomes an acceptable cost of doing business. Fielding customer complaints because they couldn't ride due to an offline reader isn't free either.
beeflet 1y ago
Not nessisarially because it can take advantage of TEEs in smart cards
raincole 1y ago
In Taiwan, there is a similar system called EasyCard. That works offline. ...And as you expect it is vulnerable to double spend attacks. Hilariously the vulnerability was revealed in 2014 and nothing has been done to mitigate it. Yes, you can double spend in Taiwan today if you don't mind risking jail time. From my (rudimentary) understanding of CAP, there is no prefect solution to this. I wonder how Japan handles it.
- account42 1y ago
  You can also "double spend" cash with fake bills. Zero fraud is never a reasonable design goal. Much easier than double spending would be to use a student or other reduced fare card.

mappu 1y ago

I think a lot of the motivations are AML. Suica has a low maximum balance, that probably restricts the nefarious use cases.

Shank 1y ago
I would personally argue that 20,000 yen is not a low maximum balance for day-to-day purchases like food, because you can recharge so easily. Before Suica (and a bit concurrently), JNR and later JR issued "orange cards" that included both high value formats and lower value formats. The "high value" cards were 5,000 yen and 10,000 yen respectively, so the new maximum is 2x the previous "high value" orange cards that they abolished. The real win with e-money is not getting change, in my opinion. Carrying 20,000 yen in cash is easy when it's 2x 10,000 notes, but when it's a mix including coins, it's a pain.
- CapricornNoble 1y ago
  >Carrying 20,000 yen in cash is easy when it's 2x 10,000 notes, but when it's a mix including coins, it's a pain. Carry a coinpurse. I use an old faux-suede Samsung camera pouch.[1] Plus it's fun when someone is running an errand for you, like getting you a snack from the konbini across the street, and you plop your coinpurse on the desk with a thud, then pour out a handful of 500-yen coins and say "this should cover it", like a feudal lord. [1] kinda like this: https://www.amazon.ie/DFVmobile-Samsung-Galaxy-Camera-Closure/dp/B075K8TJR7 https://www.amazon.ie/DFVmobile-Samsung-Galaxy-Camera-Closur...
  - charcircuit 1y ago
    Why have a whole purse when it is already built into your phone which you already are carrying around anyways.
    - account42 1y ago
      Because my coin purse isn't going to randomly decide that it doesn't like the transaction.

cosmotic 1y ago

Meanwhile, there's no apparent way to pay for a train using an American android phone (or at least I couldn't figure it out last year). One of the two apps refused to install on non-japanese phones, the other installed but refused to run. Had to pay with cash and it was a huge pain. Half the time I inexplicably had to do a fare adjustment, a hugely embarrassing moment blocking the turnstile, especially considering the culture there.

cosmic_cheese 1y ago
That’s thanks to Android phone manufacturers, which don’t want to pay for a global license for the NFC tech involved. Apple on the other hand does pay for a global license and so iPhones and Apple Watches from anywhere work perfectly with Japanese cash card terminals. I use a digital Suica on my US iPhone during my visits. Supposedly Pixels have the requisite hardware, but Google software locks the functionality to Japan. Some have been able to hack their Pixels to force it on but from what I’ve gathered it’s flaky when you do that.
- seabass-labrax 1y ago
  Why should they pay for a licence? Once a technology reaches such ubiquity, there's a strong case for it being part of the technical infrastructure of that society. To me, that means that governments have a responsibility to ensure that the technology is widely available, and arbitrarily locking it behind commercial licences does not help achieve that. To the extent that patents and licensing provide an incentive to develop such technology, it's beholden on governments to foot the R&D bill in some other way.
  - cosmic_cheese 1y ago
    I see your point, but at the same time fracturing product lines into a million micro-SKUs also isn’t great and should be discouraged.
  - lmz 1y ago
    Using this sort of logic Windows would be mandatory and paid for by the government on all your 90s, 2000s laptops.

mapt 1y ago

Those prepaid visa cards don't actually exist, I think they were killed by AML/KYC. Instead, they appear to be "prepaid visa gift cards" accepted at less than a hundred large chains.

Larrikin 1y ago
This is wrong. The visa gift cards work pretty much everywhere, unless they are specifically disabled by the establishment. They do show as a gift card but all the POS systems are perfectly capable of splitting the payment now. I've only seen them disabled at small restaurants that have dealt with scam charge backs and sites like Raise that deal in gift cards and gift card scams as part of their business. Usually they simply aren't worth it because of the activation fee. It's always more than the highest paying credit card cash back. However sometimes stores, run sales where they waive the activation fee, but there's always a limit.

m463 1y ago

to me suica seemed limited (for a traveler). you could get one and charge it up with a credit card, but I don't think you could recharge it that way. You could also not get multiple ones. I believe there is a less limited suica card you can get (not a traveler), but I think you need a japanese address.

Shank 1y ago
> I believe there is a less limited suica card you can get (not a traveler), but I think you need a japanese address. You don’t need a Japanese address. Simply visit any Suica vending machine, change the language to English, and purchase anonymous Suica. There are various preloaded options you can purchase, but typically you cannot recharge e-money via cash.
- m463 1y ago
  the vending machine card was the red one, right? I though there was a (blue?) one that japanese citizens could get, sent to their address.
  - veeti 1y ago
    The red is a 30 day card for tourists. The green is valid for many years. You can get both anonymously, but there was a chip shortage a while back which meant only the red cards were widely available.
  - Shank 1y ago
    > I though there was a (blue?) one that japanese citizens could get, sent to their address. No, there are no citizen specific IC cards unless you want extremely esoteric ones, like for senior citizens or children. All of the major nationwide mutual use transportation IC cards are freely available at the stations their operators carry. That's anything in the red box on this chart: https://en.wikipedia.org/wiki/Suica#/media/File:ICCard_Connection_en.svg https://en.wikipedia.org/wiki/Suica#/media/File:ICCard_Conne....
  - socalgal2 1y ago

lisbbb 1y ago

But Japanese people largely still use cash, don't they?

trenchpilgrim 1y ago
This isn't as true as it used to be. Mobile pay and IC-type cards have risen in popularity, and if you have a credit card, it's accepted in many places.
lofties 1y ago
This is no longer true. With the advance of "cashless" systems that were heavily pushed and promoted by the government, cash payments have dropped significantly![0] Cashless payments now sit near 50%, up from 16% 10 years ago. [0]https://www.meti.go.jp/english/press/2025/0331_001.html https://www.meti.go.jp/english/press/2025/0331_001.html
- rendaw 1y ago
  But not the anonymous, offline, accessible payment systems this thread is about. The online, ad infested phone-app-only, less accessible "cashless" systems like paypay. Even today the only place you can buy food with your pasmo/suica card is at the convenience store. Why is that?
Gathering6678 1y ago
From my experience, apart from small restaurants and yatais (basically food carts), as well as local buses in small towns, you could get by using a credit card / Suica perfectly fine.

ekianjo 1y ago

Suica is far from being accepted everywhere. in Japan cash is your best bet.

wakawaka28 1y ago

Keep in mind that "anonymous" money systems are not untrackable. You need to have killer OpSec to actually have an anonymous digital wallet even if it is technically possible. I'd rather not deal with that extreme discipline. Cash does the job just fine, at least for in-person transactions.