<p>Ripple doesn't support anything like this directly. You could get the effect if you really needed it though. Simply create a new account and extend the amount of total trust you want to that new account. Then have the new account extend the individual trust to each of the other accounts.</p>

<p>This will mean that people paying you with IOUs from any of the accounts in the group will have to ripple their payments through the new account you created because you won't accept those IOUs directly. You will wind up with IOUs from the new account regardless of which IOUs from the group they try to pay you with and your new account will hold the real IOUs. So the credit you extend to the new account will limit the total amount of IOUs from that group you can hold.</p>

<p>When you make an outbound payment, you'll go through the new account and reverse the process, trading in the IOUs from the new account for the "real" IOUs.</p>

CC BY-SA 3.0
2013-02-26T16:27:42.250Z
That doesn't really have the same effect. There should be a continuous decrease in the credit for each user as the total amount of IOUs held increases.
Meni Rosenfeld
CC BY-SA 3.0
2013-02-26T16:28:03.543Z
I'd like to say I think this is a real problem. It's not a specialized use case, it's how credit relationships work naturally. Lacking such a feature will lead to either 1. Using too small credits to minimize worst case scenarios, limiting the usefulness of the system, or 2. Having frequent, devastating collapses as people overextend themselves. That said it might be solvable client-side, adjusting credit values automatically using specified rules.
Meni Rosenfeld
CC BY-SA 3.0
2013-02-28T01:58:34.383Z
@MeniRosenfeld: I think that's what this does, unless I'm misunderstanding you. The effective credit line for each user is the lower of what remains on the credit line between that user and the intermediary account and what remains on the credit line between the intermediary account and the main account.
David Schwartz
CC BY-SA 3.0
2013-02-28T06:47:08.337Z
No, it needs to scale down continuously, see the example in the question. Another highly simplified example (not exact numbers): I give $10K credit to A, B and C with total credit $20K. If I Get $10K IOU from A, I will only accept up to $6K IOU from B. After I get that I will accept up to $4K from C. In your suggestion, I'll be willing to simultaneously hold $10K from both A and B. The total credit is what I'm willing to risk if it's distributed reasonably between my trustees, not with just a small subset of them.
Meni Rosenfeld
CC BY-SA 3.0
2013-02-28T09:24:01.063Z
IF what you want is a global maximum trust, the proxy account does exactly that.
In your last example with total credit 20k and 10k for each A, B and C...If you have 10k from A, then B and C combined can only pay you up to 10k. If B owes you 8k, there's only 2k left for C to owe you. 

I don't understand why would you want something like this:

"...my total trust is $50K. If I hold $20K IOUs from others, I will automatically only accept up to $6K from A. ($10K * (1 - $20K / $50K))"
Why do you divide 20k / 50k?
jtimon
CC BY-SA 3.0
2013-02-26T15:20:38.487Z
2013-02-26T15:20:38.487Z
David Schwartz
<p>Ripple allows us to encode how much we trust each person. For example, I can trust A with $10K and B with $10K, and will then accept IOUs of up to $10K from each as valid dollars.</p>

<p>In the real world, this does not mean I would trust them both with $10K <em>at the same time</em>. Perhaps the risk associated with A and B is highly correlated, or perhaps I just don't want to risk $20K of my money with others. For example, I could trust A and B together with $15K. So if I already have a $10K IOU from A, I will only accept up to $5K IOU from B.</p>

<p>In general, I can see myself trusting 10 different people with $10K, but certainly not trusting them all together with $100K.</p>

<p>Does Ripple allow encoding correlated trust relationships, or at least a specification of "total" trust? For example, I could define some trust relationships, including $10K to A; and I will further define that my total trust is $50K. If I hold $20K IOUs from others, I will automatically only accept up to $6K from A. ($10K * (1 - $20K / $50K))</p>

CC BY-SA 3.0
2013-02-26T21:52:03.903Z
Interesting problem.
ripper234
CC BY-SA 3.0
2013-08-27T17:30:33.923Z
I just explained ripple to a colleague and we came to the same conclusion: It would be nice to be able to set a maximum amount of trust to the network.
Murch
<ripple><iou>
Does Ripple support subadditive trust?
Meni Rosenfeld
# Does Ripple support subadditive trust?

(Asked by: username_0 on 2013-02-26)

Ripple allows us to encode how much we trust each person. For example, I can trust A with $10K and B with $10K, and will then accept IOUs of up to $10K from each as valid dollars.

In the real world, this does not mean I would trust them both with $10K *at the same time*. Perhaps the risk associated with A and B is highly correlated, or perhaps I just don't want to risk $20K of my money with others. For example, I could trust A and B together with $15K. So if I already have a $10K IOU from A, I will only accept up to $5K IOU from B.

In general, I can see myself trusting 10 different people with $10K, but certainly not trusting them all together with $100K.

Does Ripple allow encoding correlated trust relationships, or at least a specification of "total" trust? For example, I could define some trust relationships, including $10K to A; and I will further define that my total trust is $50K. If I hold $20K IOUs from others, I will automatically only accept up to $6K from A. ($10K \* (1 - $20K / $50K))

**Tags:** ripple, iou

> **Comments:**
> **username_1**: Interesting problem.  
> **username_2**: I just explained ripple to a colleague and we came to the same conclusion: It would be nice to be able to set a maximum amount of trust to the network.  

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## 1 answers

### Answer by username_3 on 2013-02-26. Score: 6 | Accepted answer

Ripple doesn't support anything like this directly. You could get the effect if you really needed it though. Simply create a new account and extend the amount of total trust you want to that new account. Then have the new account extend the individual trust to each of the other accounts.

This will mean that people paying you with IOUs from any of the accounts in the group will have to ripple their payments through the new account you created because you won't accept those IOUs directly. You will wind up with IOUs from the new account regardless of which IOUs from the group they try to pay you with and your new account will hold the real IOUs. So the credit you extend to the new account will limit the total amount of IOUs from that group you can hold.

When you make an outbound payment, you'll go through the new account and reverse the process, trading in the IOUs from the new account for the "real" IOUs.

> **Comments:**
> **username_0**: That doesn't really have the same effect. There should be a continuous decrease in the credit for each user as the total amount of IOUs held increases.  
> **username_0**: I'd like to say I think this is a real problem. It's not a specialized use case, it's how credit relationships work naturally. Lacking such a feature will lead to either 1. Using too small credits to minimize worst case scenarios, limiting the usefulness of the system, or 2. Having frequent, devastating collapses as people overextend themselves. That said it might be solvable client-side, adjusting credit values automatically using specified rules.  
> **username_3**: @username_0: I think that's what this does, unless I'm misunderstanding you. The effective credit line for each user is the lower of what remains on the credit line between that user and the intermediary account and what remains on the credit line between the intermediary account and the main account.  
> **username_0**: No, it needs to scale down continuously, see the example in the question. Another highly simplified example (not exact numbers): I give $10K credit to A, B and C with total credit $20K. If I Get $10K IOU from A, I will only accept up to $6K IOU from B. After I get that I will accept up to $4K from C. In your suggestion, I'll be willing to simultaneously hold $10K from both A and B. The total credit is what I'm willing to risk if it's distributed reasonably between my trustees, not with just a small subset of them.  
> **username_4**: IF what you want is a global maximum trust, the proxy account does exactly that. In your last example with total credit 20k and 10k for each A, B and C...If you have 10k from A, then B and C combined can only pay you up to 10k. If B owes you 8k, there's only 2k left for C to owe you.   I don't understand why would you want something like this:  "...my total trust is $50K. If I hold $20K IOUs from others, I will automatically only accept up to $6K from A. ($10K * (1 - $20K / $50K))" Why do you divide 20k / 50k?  

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