Using Yucho account overseas

[Seasider4374]

When setting my Yucho account up to pay into my Rakuten Securities account I understand that the Yucho app allowed a daily transfer limit (of 50,000yen from memory) and so I applied for the physical トケン (token?) the small calculator-esque physical device which had no (or at least a much higher) daily limit.

I'm just wondering if I can use this token overseas?

I'm assuming not as it's probably a PHS type mobile signal it operates on...

If not, can the daily limit of the Yucho app be increased?

[Tkydon]

I don't think it uses any connection.
I think it is just a One-Time-Password Key Number Generator that works with a number generator in their system, and the two keys are compared when you 'sign' the transaction.

[northSaver]

I've also wondered how it works and agree with Tkydon that it probably doesn't connect to a network. I can't find anything specific about Yucho's token but this page about Prestia's token confirms that it doesn't connect to a network and should work from overseas:
https://faq.smbctb.co.jp/faq/show/255?s ... n=smbctben

However, you should probably try to set up the Yucho Authentication App on your phone if possible. The token's battery will expire after about 5 years and it will be hard to get a new one from outside Japan (you can't change the battery yourself).

[Tsumitate Wrestler]

There are many types of security tokens, some more advanced.

These Yucho ones are the simple type. It contains and algorithm that will generate numbers from input.

That same algorithm exists on a server. So when it ask you to enter a number, it knows what the answer should be.

When these two answers match up, you are authenticated.

That is the simple explanation, perhaps someone can go into the math.

[beanhead]

Somewhat unrelated, but I don't consider Yucho a full-service bank.

For those who are able to do so, opening an account at one of the big high street banks (Mizuho etc) and an 'online' bank (Sony, Aeon) in addition to your yucho account, will probably make your life easier.

[Seasider4374]

Thanks for all replies so far.

These Yucho ones are the simple type. It contains and algorithm that will generate numbers from input.
That same algorithm exists on a server. So when it ask you to enter a number, it knows what the answer should be.
When these two answers match up, you are authenticated.

I've also wondered how it works and agree with Tkydon that it probably doesn't connect to a network.

I don't think it uses any connection.
I think it is just a One-Time-Password Key Number Generator that works with a number generator in their system, and the two keys are compared when you 'sign' the transaction.

But once my Yucho online banking screen asks me to enter "1234" on my authenticator how does the authenticator communicate with Yucho's servers to confirm "1234" was the code I entered on the physical authenticator device, and allow the transfer to proceed? Surely there has to be a connection between my authenticator device and the bank's servers to allow the transfer to proceed?

Somewhat unrelated, but I don't consider Yucho a full-service bank.
For those who are able to do so, opening an account at one of the big high street banks (Mizuho etc) and an 'online' bank (Sony, Aeon) in addition to your yucho account, will probably make your life easier.

Beanhead you pre-empted my follow-up question!
Which online banking apps are easiest to use... Down here in the 47th, Yucho's online banking interface is head and shoulders above our high street Ryukyu, and Okinawa Banks' online offerings... I have Wise setup, but would like a much more user friendly "domestic" offering as well if possible. As a Rakuten Securites account holder would Rakuten Bank (points etc) be a logical/favoured option?

[Tsumitate Wrestler]

Thanks for all replies so far.


But once my Yucho online banking screen asks me to enter "1234" on my authenticator how does the authenticator communicate with Yucho's servers to confirm "1234" was the code I entered on the physical authenticator device, and allow the transfer to proceed? Surely there has to be a connection between my authenticator device and the bank's servers to allow the transfer to proceed?

Your missing some steps.

1. You are asked to enter the account number you are transferring to into the device and press enter.
2. You typer 123456 on the fob, and press enter.
3. The device runs the algorithm and spit out a number *51556987*. This is NOT random. But Specific to the fob, and your account
5. You enter *51556987* into the Yucho website in the appropriate spot.
6. The Yucho server has this algorithm, it know for your account 123456=51556987
7. You can now log in.

[Tkydon]

I don't think it uses any connection.
I think it is just a One-Time-Password Key Number Generator that works with a number generator in their system, and the two keys are compared when you 'sign' the transaction.

The Yucho System is running a One-Time-Password Key Number Generator that complements the one on the Token.

The Token is constantly generating a time dependent One-Time Password. It doesn't talk to anyone. It just keeps generating an new one every minute or so, or on demand. The math is very complicated.

When the App asks for the One-Time Password, there is another complicated mathematical algorithm that does another operation on the Token One-Time Password you enter to see if the internally generated One-Time Password complements the one you sent. If they match, they have proved that you have the Token, and authenticate the transaction. If they don't match, then they do not allow the transaction.

The only communication required is for you to enter the One-Time Password into the App and the App sends it.

[Seasider4374]

1. You are asked to enter the account number you are transferring to into the device and press enter.
2. You typer 123456 on the fob, and press enter.
3. The device runs the algorithm and spit out a number *51556987*. This is NOT random. But Specific to the fob, and your account
5. You enter *51556987* into the Yucho website in the appropriate spot.
6. The Yucho server has this algorithm, it know for your account 123456=51556987
7. You can now log in.

Thank you. That explains a lot, but still how do my fob, and Yucho servers communicate between each other (geographically domestically, and hopefully internationally too)?

[Tsumitate Wrestler]

1. You are asked to enter the account number you are transferring to into the device and press enter.
2. You typer 123456 on the fob, and press enter.
3. The device runs the algorithm and spit out a number *51556987*. This is NOT random. But Specific to the fob, and your account
5. You enter *51556987* into the Yucho website in the appropriate spot.
6. The Yucho server has this algorithm, it know for your account 123456=51556987
7. You can now log in.

Thank you. That explains a lot, but still how do my fob, and Yucho servers communicate between each other (geographically domestically, and hopefully internationally too)?

They, DO NOT, communicate. Lets explain this simply with a metaphor.

The Yucho servers know the question, and the answer.

Yucho asks you the question, the fob generates the answer, the Yucho server confirms if it is right.

.....
The Yucho server has a list of all questions and answers.
The fob has a list of all questions and answers.
The fob will not show an answer, unless you enter the correct question.