this post was submitted on 02 May 2025
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GNU Taler for payments? (programming.dev)
submitted 3 months ago* (last edited 3 months ago) by xoron@programming.dev to c/opensource@programming.dev
 

https://www.taler.net/

"privacy friendly online transactions"

I came across this and it's looks interesting it seems to have been out for a while and seems to work well in the demo.

it sounds a bit like Blockchain, but it doesn't seem to be. which i would think makes it more appealing because the setup was easy... but i can't find any examples of it being used in the wild.

i was expecting to see more cases that used it when i saw there is funding for it from https://nlnet.nl/

i think this could be good to add into my app. but i wonder if it might not be a good idea if it hasnt established itself as reliable in the wild.

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[–] poVoq@slrpnk.net 15 points 3 months ago (2 children)

No, it is a payment system, not a pseudo currency. Think of it as an open-source Paypal.

It has been used as a digital voucher system on some events, and there is afaik a trial with a inofficial regional currency somewhere in Italy.

But mainly people are currently waiting for the first bank to offer an option to charge your Taler wallet with Euros. There is a German coop bank that plans to do so in the comming weeks.

[–] enemenemu@lemm.ee 2 points 3 months ago (2 children)

Sounds like it'll be superfluous once the digital euro wallet lands

[–] poVoq@slrpnk.net 7 points 3 months ago (1 children)

Maybe, but the digital Euro has none of the buyer's privacy protection of Taler.

I personally suspect that the digital Euro will not see much every-day uptake because it will be overly bureocratic and a hassle to use, but it might end up as an common way to charge your Taler wallet.

[–] enemenemu@lemm.ee 1 points 3 months ago

We'll see, it's not far away

[–] moonpiedumplings@programming.dev 2 points 3 months ago* (last edited 3 months ago) (1 children)

It's very possible that the digital Euro will be a GNU taler system.

https://en.wikipedia.org/wiki/GNU_Taler

n 2020 the project received a grant from NLnet and the European Commission's Horizon 2020 Next

The European Commission is the Executive Arm of the EU.

[–] enemenemu@lemm.ee 1 points 3 months ago

Commission is not involved in developing the digital euro, afaik. Am I missing something?

[–] xoron@programming.dev 1 points 3 months ago (1 children)

thanks for the clarity!

do you have any links to share about it?

[–] poVoq@slrpnk.net 7 points 3 months ago* (last edited 3 months ago)

https://www.gls.de/taler is the page of the German bank.

The forum of the ongoing project has some interesting links, but is sadly not very active: https://ich.taler.net/

[–] unexposedhazard@discuss.tchncs.de 10 points 3 months ago

Its not "out" in any sense. Its an experimental model project. Nobody really accepts it for payment afaik.

https://www.taler.net/en/faq.html

Are there any projects already using Taler?

We are aware of several businesses running exploratory projects or having developed working prototypes. We are also in discussions with several regular banks as well as several central banks about the project. That said, there are currently no products in the market yet, and we believe this would be premature given the state of the project (see also our bugtracker for a list of open issues).

[–] Kissaki@programming.dev 9 points 3 months ago

It's in a process of development and testing in Europe as an official currency/payment technology.

taler.net has a post about that - NGI Taler - too.

We may be seeing much more concrete news and use in and from two years from now.

[–] Swedneck@discuss.tchncs.de 4 points 3 months ago (1 children)

i really wish someone could explain it to me in a way that makes sense, because the concept just seems like complete magic to me

[–] Kissaki@programming.dev 2 points 3 months ago* (last edited 3 months ago)

I looked at Wikipedia; Taler then Blind signature, then looked for docs on GNU Taler where I didn't immediately find any technical overview of how that works. Phind gave me a seemingly reasonable and understandable answer. (Surely sourced from somewhere.)

When we multiply the original message by rere, sign it, and then multiply by r−1r−1, the blinding factors cancel out while preserving the signature.

The success of this process relies on two critical properties:

  • The blinding factor must be relatively prime to N
  • The RSA keypair must satisfy the congruence relation red≡r(modN)red≡r(modN)

The magic is that you can

  1. Apply a mathematical operation on your data
  2. Sign that data
  3. Revert/Invert the mathematical operation

and the signature remains valid.

It does sound like magic. But isn't most of cryptography like that?

There's a python example in there as well, with such a calculation. I didn't go through it though.