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Topic: [SDC] ShadowCash | Welcome to the UMBRA - page 571. (Read 1289714 times)

sr. member
Activity: 476
Merit: 250
September 25, 2014, 01:51:11 PM
Rhino coding,


sr. member
Activity: 350
Merit: 250
September 25, 2014, 01:43:01 PM
I've got a few question about this coin and hopefully someone can give me some answers.

1. Where's the source? Looked at both threads, the official site, the wiki and either I'm completely blind or is it not open source?

2. What method does the PoS use? Like peercoin with coin age? Like NXT? Or like the newer BC PoS V2 or Reddcoin PoSV? Or maybe something unique?

3. Is the coin based on ZeroCash? From what I've read and with the upcoming implementation of zk-snarks it would appear it is.

4. Assuming it's based on ZeroCash, I'm wondering about:

4a. "They used a brand new technic called SNARK, which has certain downsides: for example, a large initial database of public parameters required to create a signature (more than 1 GB) and the significant time required to create a transaction (more than a minute)" - What does all this really mean and what, in terms of practical use, would it mean to users?

4b. "Another important note is about trusted setup in Zerocoin. In easy words the whole system is based on some secret values nobody should know (for example, this secret allows to make a double spend). How to acquire these values? ZC devs says: we can generate them and then "forget" OR we can implement the special algorithm to do in a distributed way at the system start (everybody know only his own part of the secret)." - does this issue also exist in Zerocash and (if Shadow uses it), ShadowCoin as well?

4c. "The proofs of Zerocash can be computed by a i7 single core 2.7 GHz CPU in a matter of 3 minutes" - What exactly are these "proofs" and again, what would this mean to regular users?

I really don't understand fully the difference between Zerocoin and ZeroCash etc so not sure if all this really would apply but maybe someone in the know could educate me.

Hi Viper

1. The project is open source, the link for the repo is on the ANN theres a little icon for Github. I can see how you would miss it though., we should probably add a link to it.  https://github.com/SDCDev/shadowcoin
2. Shadow is using coin weight/age. Any change to the PoS scheme will happen after zk.
3. ShadowSend is based on a combination of dual-key stealth addresses and zero knowledge proofs. The underlying technology in ZeroCash is zk-snarks, but the initial setup of the parameters in zerocash requires trust. Shadow is using its own zero knowledge scheme (proving a statement without revealing any information) and our setup doesn't require trust.
4a. In the WP they are referencing the initial parameters of Zerocash. Our system uses a different setup, so that issue only applies to ZC. All this translates to for the end user is that the ZC opts for a trusted setup.
4b. This is a non-issue because of 4a.
4c. https://self-evident.org/?p=995
Here's a detailed video covering the differences:
https://www.youtube.com/watch?v=FXU65XsLiFk
I've attached this pdf for zero knowledge in laymen's terms: http://pages.cs.wisc.edu/~mkowalcz/628.pdf

Awesome, thanks for the details answers.  Yeah, now that I look back at the OP, I can see the source icon there.  I just assumed those were all some sort of wallet downloads lol

So I was just looking up "dual key stealth" and came across DarkWallet. Then I came across this post of yours which actually laid it out a bit more clearly for me.

https://bitcointalksearch.org/topic/m.8153845

Am I correct if I were to say that ShadowSend is an improved derivative of DarkWallet? Or maybe that's not really fair to say as I can't figure out who actually implemented what first. lol

So right now there seems to be I guess 4 anon "methods".  We've got Darkcoin which one could argue isn't all that trustless given you need the masternodes.  Then there's CN which, near as I can tell, is generally perceived as the only "true" anon implementation out there.  I found it interesting though that one of the CN guys seemed to be saying ZeroCash was a more advanced method although I'm not sure if he also meant better. And then there's some other coin that will remain nameless that seems to be implementing some derivative of CN which they claim will resolve at least the blockchain bloat issue of CN coins.  The Monero guys recently put out a white paper outlining some issues with CN that could potentially result in exploits.

So, if we assume that CN is the "best" currently despite some of it's issues, what makes ShadowSend better and what are some of the issues with it. i.e what are the currently known Pros and Cons.

Hey Viper,

We're actually working on a overview that will chart the pros and cons of each unique anon protocol. Approaches that don't use zero knowledge either mix or mask the transaction by using nodes, pools or group signatures. ZK protocols make the transactions invisible in a way that only the sender and receiver know about the transaction. It would be the same as thinking of paying someone in cash and not keeping a receipt. The only people who would know about the transaction is the buyer and the seller. The other approaches like mixing or group signatures could be looked at as paying by cash, but using something like western union or a money order to facilitate the transaction. Although the transaction is technically cash there would be a way to figure out and/or trace the transaction some harder than others.. ZK and it's variants are the closest thing to a cash transaction in cryptography.

A couple benefits of Shadow over CN would be a compressed blockchain vs bloated one. Shadow has a Simplified Payment Verification (SPV) system in place with ShadowLite (thinmode=1) that already helps reduce the bloat.
sr. member
Activity: 476
Merit: 250
sr. member
Activity: 462
Merit: 500
September 25, 2014, 01:24:51 PM
hero member
Activity: 952
Merit: 515
September 25, 2014, 09:47:31 AM
My ShadowCash Review: http://btc-thailand.com/shadowcash-coin-review-517/

ShadowCash Score:  7.5 / 10  !

Keep up the good work!

Cheers,

Christian

PS: Lets show the Bitcointalk Community which Coin has the strongest: https://bitcointalksearch.org/topic/vote-for-the-best-podcoinsource-evaluted-coin-795723     , I praised you guys in my review  Wink Grin


Very nice review

Thanks!
sr. member
Activity: 686
Merit: 320
September 25, 2014, 04:56:07 AM
what was the block reward? just curious

If you're refering to the PoW period, it was 1 for some period of time after launch and then 400 until the end of PoW

Code:
    if (nHeight <= 0)
        nSubsidy = 0;
    else
    if (nHeight <= LAST_FAIR_LAUNCH_BLOCK)
        nSubsidy = 1 * COIN;
    else
    if (nHeight <= LAST_POW_BLOCK)
        nSubsidy = 400 * COIN;

last fair launch block until what height? 0-1000?

Code:
static const int LAST_POW_BLOCK = 31000;
static const int LAST_FAIR_LAUNCH_BLOCK = 120;
legendary
Activity: 3248
Merit: 1072
September 25, 2014, 04:54:19 AM
what was the block reward? just curious

If you're refering to the PoW period, it was 1 for some period of time after launch and then 400 until the end of PoW

Code:
    if (nHeight <= 0)
        nSubsidy = 0;
    else
    if (nHeight <= LAST_FAIR_LAUNCH_BLOCK)
        nSubsidy = 1 * COIN;
    else
    if (nHeight <= LAST_POW_BLOCK)
        nSubsidy = 400 * COIN;

last fair launch block until what height? 0-1000?
sr. member
Activity: 686
Merit: 320
September 25, 2014, 04:46:43 AM
what was the block reward? just curious

If you're refering to the PoW period, it was 1 for some period of time after launch and then 400 until the end of PoW

Code:
    if (nHeight <= 0)
        nSubsidy = 0;
    else
    if (nHeight <= LAST_FAIR_LAUNCH_BLOCK)
        nSubsidy = 1 * COIN;
    else
    if (nHeight <= LAST_POW_BLOCK)
        nSubsidy = 400 * COIN;
legendary
Activity: 3248
Merit: 1072
September 25, 2014, 04:41:14 AM
what was the block reward? just curious
sr. member
Activity: 686
Merit: 320
September 25, 2014, 04:36:21 AM
I've got a few question about this coin and hopefully someone can give me some answers.

1. Where's the source? Looked at both threads, the official site, the wiki and either I'm completely blind or is it not open source?

2. What method does the PoS use? Like peercoin with coin age? Like NXT? Or like the newer BC PoS V2 or Reddcoin PoSV? Or maybe something unique?

3. Is the coin based on ZeroCash? From what I've read and with the upcoming implementation of zk-snarks it would appear it is.

4. Assuming it's based on ZeroCash, I'm wondering about:

4a. "They used a brand new technic called SNARK, which has certain downsides: for example, a large initial database of public parameters required to create a signature (more than 1 GB) and the significant time required to create a transaction (more than a minute)" - What does all this really mean and what, in terms of practical use, would it mean to users?

4b. "Another important note is about trusted setup in Zerocoin. In easy words the whole system is based on some secret values nobody should know (for example, this secret allows to make a double spend). How to acquire these values? ZC devs says: we can generate them and then "forget" OR we can implement the special algorithm to do in a distributed way at the system start (everybody know only his own part of the secret)." - does this issue also exist in Zerocash and (if Shadow uses it), ShadowCoin as well?

4c. "The proofs of Zerocash can be computed by a i7 single core 2.7 GHz CPU in a matter of 3 minutes" - What exactly are these "proofs" and again, what would this mean to regular users?

I really don't understand fully the difference between Zerocoin and ZeroCash etc so not sure if all this really would apply but maybe someone in the know could educate me.

Hi Viper

1. The project is open source, the link for the repo is on the ANN theres a little icon for Github. I can see how you would miss it though., we should probably add a link to it.  https://github.com/SDCDev/shadowcoin
2. Shadow is using coin weight/age. Any change to the PoS scheme will happen after zk.
3. ShadowSend is based on a combination of dual-key stealth addresses and zero knowledge proofs. The underlying technology in ZeroCash is zk-snarks, but the initial setup of the parameters in zerocash requires trust. Shadow is using its own zero knowledge scheme (proving a statement without revealing any information) and our setup doesn't require trust.
4a. In the WP they are referencing the initial parameters of Zerocash. Our system uses a different setup, so that issue only applies to ZC. All this translates to for the end user is that the ZC opts for a trusted setup.
4b. This is a non-issue because of 4a.
4c. https://self-evident.org/?p=995
Here's a detailed video covering the differences:
https://www.youtube.com/watch?v=FXU65XsLiFk
I've attached this pdf for zero knowledge in laymen's terms: http://pages.cs.wisc.edu/~mkowalcz/628.pdf

Awesome, thanks for the details answers.  Yeah, now that I look back at the OP, I can see the source icon there.  I just assumed those were all some sort of wallet downloads lol

So I was just looking up "dual key stealth" and came across DarkWallet. Then I came across this post of yours which actually laid it out a bit more clearly for me.

https://bitcointalksearch.org/topic/m.8153845

Am I correct if I were to say that ShadowSend is an improved derivative of DarkWallet? Or maybe that's not really fair to say as I can't figure out who actually implemented what first. lol

So right now there seems to be I guess 4 anon "methods".  We've got Darkcoin which one could argue isn't all that trustless given you need the masternodes.  Then there's CN which, near as I can tell, is generally perceived as the only "true" anon implementation out there.  I found it interesting though that one of the CN guys seemed to be saying ZeroCash was a more advanced method although I'm not sure if he also meant better. And then there's some other coin that will remain nameless that seems to be implementing some derivative of CN which they claim will resolve at least the blockchain bloat issue of CN coins.  The Monero guys recently put out a white paper outlining some issues with CN that could potentially result in exploits.

So, if we assume that CN is the "best" currently despite some of it's issues, what makes ShadowSend better and what are some of the issues with it. i.e what are the currently known Pros and Cons.
full member
Activity: 129
Merit: 100
Leave nothing but a shadow.
September 25, 2014, 03:23:12 AM
I've got a few question about this coin and hopefully someone can give me some answers.

1. Where's the source? Looked at both threads, the official site, the wiki and either I'm completely blind or is it not open source?

2. What method does the PoS use? Like peercoin with coin age? Like NXT? Or like the newer BC PoS V2 or Reddcoin PoSV? Or maybe something unique?

3. Is the coin based on ZeroCash? From what I've read and with the upcoming implementation of zk-snarks it would appear it is.

4. Assuming it's based on ZeroCash, I'm wondering about:

4a. "They used a brand new technic called SNARK, which has certain downsides: for example, a large initial database of public parameters required to create a signature (more than 1 GB) and the significant time required to create a transaction (more than a minute)" - What does all this really mean and what, in terms of practical use, would it mean to users?

4b. "Another important note is about trusted setup in Zerocoin. In easy words the whole system is based on some secret values nobody should know (for example, this secret allows to make a double spend). How to acquire these values? ZC devs says: we can generate them and then "forget" OR we can implement the special algorithm to do in a distributed way at the system start (everybody know only his own part of the secret)." - does this issue also exist in Zerocash and (if Shadow uses it), ShadowCoin as well?

4c. "The proofs of Zerocash can be computed by a i7 single core 2.7 GHz CPU in a matter of 3 minutes" - What exactly are these "proofs" and again, what would this mean to regular users?

I really don't understand fully the difference between Zerocoin and ZeroCash etc so not sure if all this really would apply but maybe someone in the know could educate me.

Hi Viper

1. The project is open source, the link for the repo is on the ANN theres a little icon for Github. I can see how you would miss it though., we should probably add a link to it.  https://github.com/SDCDev/shadowcoin
2. Shadow is using coin weight/age. Any change to the PoS scheme will happen after zk.
3. ShadowSend is based on a combination of dual-key stealth addresses and zero knowledge proofs. The underlying technology in ZeroCash is zk-snarks, but the initial setup of the parameters in zerocash requires trust. Shadow is using its own zero knowledge scheme (proving a statement without revealing any information) and our setup doesn't require trust.
4a. In the WP they are referencing the initial parameters of Zerocash. Our system uses a different setup, so that issue only applies to ZC. All this translates to for the end user is that the ZC opts for a trusted setup.
4b. This is a non-issue because of 4a.
4c. https://self-evident.org/?p=995
Here's a detailed video covering the differences:
https://www.youtube.com/watch?v=FXU65XsLiFk
I've attached this pdf for zero knowledge in laymen's terms: http://pages.cs.wisc.edu/~mkowalcz/628.pdf
sr. member
Activity: 686
Merit: 320
September 25, 2014, 02:00:22 AM
I've got a few question about this coin and hopefully someone can give me some answers.

1. Where's the source? Looked at both threads, the official site, the wiki and either I'm completely blind or is it not open source?

2. What method does the PoS use? Like peercoin with coin age? Like NXT? Or like the newer BC PoS V2 or Reddcoin PoSV? Or maybe something unique?

3. Is the coin based on ZeroCash? From what I've read and with the upcoming implementation of zk-snarks it would appear it is.

4. Assuming it's based on ZeroCash, I'm wondering about:

4a. "They used a brand new technic called SNARK, which has certain downsides: for example, a large initial database of public parameters required to create a signature (more than 1 GB) and the significant time required to create a transaction (more than a minute)" - What does all this really mean and what, in terms of practical use, would it mean to users?

4b. "Another important note is about trusted setup in Zerocoin. In easy words the whole system is based on some secret values nobody should know (for example, this secret allows to make a double spend). How to acquire these values? ZC devs says: we can generate them and then "forget" OR we can implement the special algorithm to do in a distributed way at the system start (everybody know only his own part of the secret)." - does this issue also exist in Zerocash and (if Shadow uses it), ShadowCoin as well?

4c. "The proofs of Zerocash can be computed by a i7 single core 2.7 GHz CPU in a matter of 3 minutes" - What exactly are these "proofs" and again, what would this mean to regular users?

I really don't understand fully the difference between Zerocoin and ZeroCash etc so not sure if all this really would apply but maybe someone in the know could educate me.
full member
Activity: 324
Merit: 100
September 25, 2014, 12:51:47 AM
Ive heard some interesting things about this coin, whats it all about?

Quote from: Coolstoryteller
ShadowCash

zk-snarks is one of the biggest advancements in cryptography at the moment, especially in relation to anonymity and blockchain compression. Adoption of zk-snarks will finally put the anon debate to rest once and for all. It's even acknowledged as superior by Maurice P, one of the founders of cryptonote.

"[Maurice P]Zerocoin, Zerocash. This is the most advanced technology, I must admit. Yes, the quote above [from the white paper] is from the analysis of the previous version of the protocol. To my knowledge, its not 288, but 384 bytes, but anyway this is good news [the latest trimming of sizes]. They used a brand new technique [sic] called SNARK, which has certain downsides: for example, large initial database of public parameters required to create a signature (more than 1 GB) and significant time required to create a transaction (more than a minute). Finally, they're using a young crypto, which I've mentioned to be an arguable idea: https://forum.cryptonote.org/viewtopic.php?f=2&t=19#p55"

-Maurice P.

"Now, notice that since we are still pushing information through a function (our random oracle function), and not using a zero-knowledge system, our system is still not fully zero-knowledge anonymous."

http://monero.cc/downloads/whitepaper_review.pdf

Shadow already has a working Simplified Payment Verification (SPV) system in place with the latest ShadowLite release, that addresses some of the concerns about the signature; In addition, the proof sizes are even smaller than the ones quoted by Maurice. ShadowCash's approach is quite different to Zerocoin/ZeroCash. All in all the coming weeks will be very interesting for the anon space with Shadow. No doubt the only real investment right now in the anon space is Shadow. Investing in anything else in the anon space right now is pointless, as Shadow will wrapping up the anon debate.


List of 1sts:

Open sourced dual key stealth addresses (ShadowSend)
Android wallet for Proof of Stake (ShadowGo)
iOS wallet for Proof of Stake (ShadowGo)
Simplified Payment Verification (SPV) system for Proof of Stake (ShadowLite)
Modular HTML5 wallet
Anonymous contact discovery for Encrypted Messaging System (ShadowChat)


The list grows and it's clear that the only coin on that list actually progressing crypto forward by original innovation in ShadowCash. Invest in hype or invest in actual development the choice is yours. The only real PoD is Proof of Development and Shadow eclipses every other coin on the list in that department.
member
Activity: 109
Merit: 10
September 25, 2014, 12:46:36 AM
Ive heard some interesting things about this coin, whats it all about?
sr. member
Activity: 350
Merit: 250
hero member
Activity: 840
Merit: 1000
September 24, 2014, 09:10:07 PM
http://weibo.com/shadowcash   China SDC commnity weibo account
legendary
Activity: 1190
Merit: 1002
Pecvniate obedivnt omnia.
September 24, 2014, 08:53:28 PM
Shadow has huge potential to take off in china, good work.
legendary
Activity: 1078
Merit: 1050
September 24, 2014, 08:46:43 PM

Good effort thanks a lot fox, cant wait till they see shadow in china Smiley
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