Indiegogo launch - help us! :o

[AB de Royse777]

certainly not universally perfect solution.

I don't think there is any universally perfect solution. We all try and give the best. While I don't understand everything that OP is trying to do but I feel that he is trying something on top of the existing options we have. Every good initiative worth trying.

Take a look in the post comparing the pros and cons: https://www.cryptoplatz.ch/post/safe-guard-your-crypto-assets-with-fool-proof-seed-phrase-storage-1

I was looking at the differences. These comparisons between a software run device and a piece of metal is actually not relevant at all.

A metal really does not need to have encrypted. With a cleaver combination someone easily can hide some information which even if it ends up to the wrong guy still they can not get the idea of what was there.
In a metal sheet it's obviously does not make sense to have password.
Well nothing has forever warranty or guarantee
Open source of course nothing to do with a piece of metal.

[1713891485]

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[1713891485]

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[1713891485]

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[1713891485]

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[cryptoplatz]

The password is optional, if you use, will be encrypted.

Am I correct in assuming that without the password, anyone that gets their hands on the metal card in question, can easily decrypt or rather access the information that's stored in it?

The question is also what is stored. Is it a plain text (words) or for example entropy (as seed words <-> entropy are exchangeable). But it would require an algorithm inside the application which would "understand" the seed words (verify checksum etc). And I suppose it would not support seeds other than BIP39, maybe would be even limited to English dictionary. Much simpler would be to store any text provided by user, without parsing it.

Hi

The CryptoPlatz App and Card (vault) accept any text (passwords, mnemonics, 12 words, 24 words, bip39...) in any language (English, French, Spanish, Portuguese, Chinese...).

If you use a password to encrypt, the text will be encypted with AES-256. Does not matter what text is it.

If somebody put the hands in you paper or cryptosteel, he can read and stole your crypto. But if you store your seed in CryptoPlatz Card, he can't ready and stole, because is encrypted.

The password is optional, if you use, will be encrypted.

Wait a minute, if password is only optional than there is no real difference compared to regular paper or metal plate.

Yes, you are correct. This is a prototype in PVC. Because that we are on https://www.indiegogo.com/projects/cryptoplatz-card to manufactory in metal stainless.

I guess you could create some free campaign or beta testing for this prototype PVC cards, and if everything works fine you could probably collect funds easier on indiegogo.
Problem I have with stainless steel material over NFC chip is that it could block the antenna signal and not work in the real life.

Yes, but they can't have my coins if I have one or more strong passphrases on top of my paper or metal plate.
CryptoPlatz is encrypted, but if customer used weak password that it can be hacked and extracted by someone who knows how to do it.
I am not saying CryptoPlatzdon't have some advantages, but it's certainly not universally perfect solution.

I agree with you, it is not the best solution.

Wait a minute, if password is only optional than there is no real difference compared to regular paper or metal plate.

If you not use password, will be like a metal plate. If you use a strong password, will be equal metal plate and encrypted.  Remember, we convert the password in MD5 hash, so the password will always have 128 bits and 32 characters.

I guess you could create some free campaign or beta testing for this prototype PVC cards, and if everything works fine you could probably collect funds easier on indiegogo.

Good idea! We are working to produce 20 cards in PVC with the logo and testing on the app. So next step, is to send for somebody that want to test

certainly not universally perfect solution.

I don't think there is any universally perfect solution. We all try and give the best. While I don't understand everything that OP is trying to do but I feel that he is trying something on top of the existing options we have. Every good initiative worth trying.

Take a look in the post comparing the pros and cons: https://www.cryptoplatz.ch/post/safe-guard-your-crypto-assets-with-fool-proof-seed-phrase-storage-1

https://i.ibb.co/hB7jP5Z/Screenshot-1.png
I was looking at the differences. These comparisons between a software run device and a piece of metal is actually not relevant at all.

A metal really does not need to have encrypted. With a cleaver combination someone easily can hide some information which even if it ends up to the wrong guy still they can not get the idea of what was there.
In a metal sheet it's obviously does not make sense to have password.
Well nothing has forever warranty or guarantee
Open source of course nothing to do with a piece of metal.

I agree with you, but save encrypted it is a good feature. But, if somebody don't want to encrypt, he can save in plain text, like metal plate.


We have published our open source code on GitHub

https://github.com/cryptoplatz-vault/cryptoplatz

There is a link on website too for the GitHub
https://www.cryptoplatz.ch/

Transparency + liberty of choice!





Hi

I need your help again from all of you. What do you think will be a good price to sell? Our plain is to sell for $ 100,00 But we would like to know your opinion.

If we change the Indiegogo campaign for example to $ 50,00 are you going to buy on Indiegogo today?

[moderator's note: consecutive posts merged]

[Mbitr]

Hi

I need your help again from all of you. What do you think will be a good price to sell? Our plain is to sell for $ 100,00 But we would like to know your opinion.

If we change the Indiegogo campaign for example to $ 50,00 are you going to buy on Indiegogo today?

I would have a good look at a few factors -
1. Costs - production, postage, website, wages, advertising and anything thing else - don’t forget anything !
2. Your DIRECT competitors prices
3. Future of the company and product - will you be producing version 2, limited editions etc
Have you produced a business plan? If not, do one - it may sound boring, but it will help.
Hope this helps and importantly, don’t sell yourself short 

[cryptoplatz]

Hi

I need your help again from all of you. What do you think will be a good price to sell? Our plain is to sell for $ 100,00 But we would like to know your opinion.

If we change the Indiegogo campaign for example to $ 50,00 are you going to buy on Indiegogo today?

I would have a good look at a few factors -
1. Costs - production, postage, website, wages, advertising and anything thing else - don’t forget anything !
2. Your DIRECT competitors prices
3. Future of the company and product - will you be producing version 2, limited editions etc
Have you produced a business plan? If not, do one - it may sound boring, but it will help.
Hope this helps and importantly, don’t sell yourself short 

Hi Mbitr

Thank you for your advice! You are correct!

Best
www.cryptoplatz.ch

[AB de Royse777]

OP it's better if you compile all response in a single post rather than making several posts for several responses. Like you did 1, 2, 3, 4. We all are abide by some unofficial rules which you will find here: https://bitcointalk.org/index.php?topic=703657.0

Anyway good luck with your project.

[cryptoplatz]

OP it's better if you compile all response in a single post rather than making several posts for several responses. Like you did 1, 2, 3, 4. We all are abide by some unofficial rules which you will find here: https://bitcointalk.org/index.php?topic=703657.0

Anyway good luck with your project.

ok I will

[dkbit98]

I need your help again from all of you. What do you think will be a good price to sell? Our plain is to sell for $ 100,00 But we would like to know your opinion.

If we change the Indiegogo campaign for example to $ 50,00 are you going to buy on Indiegogo today?

I don't know how much is production cost going to be to assemble Crypto Platz, and that is probably depending on location of country you are ordering all the source materials.
For Indiegogo campaign price of $50 would be much better, and it's comparable with stainless steel plates and some other cards that store seed words.
I am not sure if I would pre-order this card right now before I see some early testing reviews, but you could give reduced price and start spreading the word on twitter and social media.

[cryptoplatz]

I need your help again from all of you. What do you think will be a good price to sell? Our plain is to sell for $ 100,00 But we would like to know your opinion.

If we change the Indiegogo campaign for example to $ 50,00 are you going to buy on Indiegogo today?

I don't know how much is production cost going to be to assemble Crypto Platz, and that is probably depending on location of country you are ordering all the source materials.
For Indiegogo campaign price of $50 would be much better, and it's comparable with stainless steel plates and some other cards that store seed words.
I am not sure if I would pre-order this card right now before I see some early testing reviews, but you could give reduced price and start spreading the word on twitter and social media.

Now we are giving 50% discount exclusive for Indiegogo campaign, CryptoPlatz Vault now is €49,00. The campaign will finish in less than 30 days.

Thank you for advices

[n0nce]

+ Resistant to fire, water, bugs, shock wave and rust (better than a piece of paper)

My reply to this would be that you can have multiple pieces of paper / multiple backups for just pennies, so if one backup location burns down, you have another backup elsewhere. That's good practice anyway (e.g. in a flood, that metal plate can easily be flushed out of your home), but too expensive to do with expensive metal cards.

+ Easy to use with NFC (no more metal letters)

Now, here it gets tricky. How do I write my seed phrase to this device, that is supposed to be super offline and super safe, whilst at the same time needing to use my phone for the process? I will never ever type my seed phrase into a phone app, so what to do?
On paper, I can write with a pen, and even a USB thumb drive is writeable by a live Tails OS. Would I need an external NFC transceiver for my offline PC? Does such thing exist and if so, is that open-source in its hardware and software / drivers?

Compare Crypto Platz Card with others options:
https://www.cryptoplatz.ch/post/comparing-seed-phrase-backup

Unfortunately, offline.

[cryptoplatz]

+ Resistant to fire, water, bugs, shock wave and rust (better than a piece of paper)

My reply to this would be that you can have multiple pieces of paper / multiple backups for just pennies, so if one backup location burns down, you have another backup elsewhere. That's good practice anyway (e.g. in a flood, that metal plate can easily be flushed out of your home), but too expensive to do with expensive metal cards.

+ Easy to use with NFC (no more metal letters)

Now, here it gets tricky. How do I write my seed phrase to this device, that is supposed to be super offline and super safe, whilst at the same time needing to use my phone for the process? I will never ever type my seed phrase into a phone app, so what to do?
On paper, I can write with a pen, and even a USB thumb drive is writeable by a live Tails OS. Would I need an external NFC transceiver for my offline PC? Does such thing exist and if so, is that open-source in its hardware and software / drivers?

Compare Crypto Platz Card with others options:
https://www.cryptoplatz.ch/post/comparing-seed-phrase-backup

Unfortunately, offline.

Hi

I agree with you, better to have more than one card. Depends of how much cryptocurrency you have, $ 49 by card make sense.

For now our app is only for iOS and Android, but soon we will have a version for desktop. So you can use any NFC reader/writer to connect on your desktop.

And yes, you can do all operations offline, airplane mode for example (we recommend this on app)

You need to decide what is better, leave your current seed only on paper or type the seed on CryptoPlatz App to save encrypted on the card, offline.

[dkbit98]

For now our app is only for iOS and Android, but soon we will have a version for desktop. So you can use any NFC reader/writer to connect on your desktop.

n0nce has a point, people don't want to be online at all when they are dealing with their seed words.
Device with CryptoPlatz app needs to be online to download and install it, so desktop app is must have option for everyone.
Airplane mode but most people could make a mistake and just used app online.

Can you tell me what android version is oldest supported by your app?
Older phones might not be able to install app so that could be one more issue I faced before with other Android apps.

[cryptoplatz]

For now our app is only for iOS and Android, but soon we will have a version for desktop. So you can use any NFC reader/writer to connect on your desktop.

n0nce has a point, people don't want to be online at all when they are dealing with their seed words.
Device with CryptoPlatz app needs to be online to download and install it, so desktop app is must have option for everyone.
Airplane mode but most people could make a mistake and just used app online.

Can you tell me what android version is oldest supported by your app?
Older phones might not be able to install app so that could be one more issue I faced before with other Android apps.

You can find the list of compatible Android and iOS smartphones on the faq: https://www.cryptoplatz.ch/support

But I will paste here:

Acer Cloud Mobile
Acer E320 Liquid Express
Acer Liquid Glow
Acer Liquid S2
Adlink IMX-3000
Alcatel Idol 4
Alcatel One Touch 922
Alcatel One Touch 996
Alcatel Onetouch Idol 2
Alcatel Onetouch Idol 2 Mini S
Alcatel Onetouch Idol 2S
Alcatel Onetouch Pop Fit
Apple iPhone 11 and iPhone 11 Pro
Apple iPhone 12, iPhone 12 mini, iPhone 12 Pro, iPhone 12 Pro Max
Apple iPhone 13, iPhone 13 mini, iPhone 13 Pro, iPhone 13 Pro Max
Apple iPhone 6 and iPhone 6 Plus
Apple iPhone 6s and iPhone 6s Plus
Apple iPhone 7 and iPhone 7 Plus
Apple iPhone 8 and iPhone 8 Plus
Apple iPhone SE
Apple iPhone X
Apple iPhone XR
Apple iPhone Xs and iPhone Xs Max
Apple Watch
Archos New Diamond
Asmaitha Sruta 7″ Tablet
Asus MeMO Pad 8 (ME581CL)
Asus Padfone 2
Asus Padfone Infinity
Asus Vivo Tab
Asus Vivo Tab RT
Asus VivoTab Smart
Asus ZenFone 2
Asus Zenfone 4
Asus Zenfone 5
Asus Zenfone 6
BBK Vivo Xplay
Benq T80
BlackBerry Bold 9790
BlackBerry Bold 9900/9930
BlackBerry Classic
BlackBerry Curve 9350/9360/9370
BlackBerry Curve 9380
BlackBerry Dtek50
BlackBerry Dtek60
BlackBerry KEY2
BlackBerry KEYone
BlackBerry Motion
BlackBerry Passport
BlackBerry PlayBook
BlackBerry Priv
BlackBerry Q10
BlackBerry Q5
BlackBerry Z10
BlackBerry Z30
Blackview BV9800
Blackview BV9800 Pro
Blu Life Pure XL
BQ Aquaris M5.5
BWC ToughSlate 7″
C-Mii 1
C-Mii 3
Casio DT-X8
Casio G’zOne CA-201L
Casio IT-800
Cat S60
Cetrix CB250
Cetrix CD661
Cetrix CT973G
Cetrix CV300
Dell Venue 11 Pro
DLI 9000
Doogee S60 and S60 Lite
Doogee S70 and S70 Lite
Doogee S80 and S80 Lite
Elephone P9000
Essential PH-1
Faea F1
Faea F2
Faea F2S
Fairphone 3
Famoco FX-100
Firefox OS Flame
Fujitsu Arrows A
Fujitsu Arrows µ F-07D
Fujitsu Arrows Kiss
Fujitsu Arrows Tab
Fujitsu Arrows V
G.To N800
Gentag GT-601v2
Gionee Elife E7
Google Nexus 10
Google Nexus 5
Google Nexus 5X
Google Nexus 6
Google Nexus 6P
Google Nexus 7 (2013)
Google Nexus 9
Google Pixel
Google Pixel 2 and Google Pixel 2 XL
Google Pixel XL
Google Project Tango tablet
Hike X1
Hike X1D
Hisense Sero 7 Pro
HP Elitebook Revolve
HP Elitepad 900
HTC Desire 500
HTC Desire 510
HTC Desire 610
HTC Desire 620
HTC Desire 816
HTC Desire C
HTC Desire Eye
HTC Droid DNA/HTC J Butterfly
HTC Droid Incredible 4G LTE
HTC Evo 4G LTE
HTC First
HTC Incredible
HTC Mini
HTC One
HTC One M8
HTC One M9
HTC One Max
HTC One SV
HTC One VX
HTC One X/XL
HTC Ruby/Amaze 4G
HTC U Play
HTC U Ultra
HTC U11
HTC Windows Phone 8X
Huawei Ascend G300
Huawei Ascend G6 4G
Huawei Ascend G600
Huawei Ascend G7
Huawei Ascend Mate 7
Huawei Ascend P2
Huawei Ascend P7
Huawei Ascend Y201
Huawei G620S
Huawei Honor 6
Huawei Honor 8
Huawei Honor 9
Huawei Mate 10 and Huawei Mate 10 Pro
Huawei Mate 8
Huawei Mate 9
Huawei P10
Huawei P10 Plus
Huawei P8
Huawei Sonic/Turkcell T20
Huawei TalkBand B1
iBerry Auxus Nuclea N2
iOcean X8
Jolla by Jolla
Kuoziro FT701W NFC Tablet
Kyocera Duraforce Pro
Kyocera Hydro Elite
Kyocera Hydro Icon
Kyocera Hydro Vibe
Kyocera Torque
Lenovo K800
Lenovo ThinkPad Tablet 2
Lenovo Vibe X3
LG Fx0
LG G Flex
LG G Flex 2
LG G Pro 2
LG G2
LG G3
LG G3 Beat/LG G3 S
LG G4
LG G5
LG G6
LG G7 ThinQ
LG Intuition
LG KU380-NFC
LG L50
LG L70
LG L90
LG Mach
LG Optimus 3D Max
LG Optimus 4X HD
LG Optimus Elite
LG Optimus G
LG Optimus L5
LG Optimus L7
LG Optimus LTE
LG Optimus LTE Tag
LG Optimus Net
LG Optimus Vu
LG Phoenix 2
LG T530 Ego
LG V10
LG V20
LG Viper
LG Volt
Lumigon T2
Lumigon T2 HD
Lumigon T3
Megafon Mint
Meizu MX3
Meizu MX4 Pro
Microsoft Lumia 640
Microsoft Lumia 650
Microsoft Lumia 950
Microsoft Lumia 950 XL
Moto G5S/Moto G5S Plus
Motorola Droid Maxx
Motorola Droid Mini
Motorola Droid Razr
Motorola Droid Razr HD
Motorola Droid Razr M
Motorola Droid Razr M 4G LTE
Motorola Droid Razr Maxx HD
Motorola Droid Turbo
Motorola Droid Turbo 2/Moto X Force
Motorola Droid Ultra
Motorola MC75A HF
Motorola Moto E4
Motorola Moto G5 Plus
Motorola Moto G6/Moto G6 Plus
Motorola Moto G7/Moto G7 Plus
Motorola Moto G8 Plus
Motorola Moto X
Motorola Moto X Play
Motorola Moto X4
Motorola Moto Z
Motorola Moto Z Play
Motorola Moto Z2 Force
Motorola Moto Z2 Play
Motorola One Action
Motorola One Vision
Motorola One Zoom
Motorola Photon Q 4G LTE
Motorola Razr D3
Motorola Razr i/MT788
MTS 975
Nextbit Robin
Nokia 3
Nokia 5
Nokia 6
Nokia 603
Nokia 700
Nokia 701
Nokia 801T
Nokia 808 PureView
Nokia C7/Astound
Nokia G50
Nokia Lumia 1020
Nokia Lumia 1520
Nokia Lumia 2520
Nokia Lumia 610 NFC
Nokia Lumia 620
Nokia Lumia 720
Nokia Lumia 730/735
Nokia Lumia 820
Nokia Lumia 830
Nokia Lumia 920
Nokia Lumia 925
Nokia Lumia 928
Nokia Lumia 930
Nokia Lumia Icon
Nokia N9
Nokia Oro
OnePlus 3
OnePlus 5
OnePlus 5T
OnePlus 6
OnePlus 7T
OnePlus 8 and OnePlus 8 Pro
OnePlus 8T
OnePlus One
Oppo Find 5
Oppo Find 7
Oppo N1
Oppo R15 Pro
Orange Infinity 996
Orange San Diego
OrientPhone P6 Plus
Panasonic BizPad
Panasonic Eluga
Panasonic Eluga Power
Pantech Discover
Pantech Sky Vega LTE
Pantech Sky Vega Racer
Philips Xenium W336
Porsche Design Huawei Mate 10
Porsche Design P’9981
Porsche Design P’9982
Prada phone by LG 3.0
Razer Phone
Razer Phone 2
Runbo X6
Samsung Ativ Odyssey
Samsung Ativ S Neo
Samsung Ativ SE
Samsung Galaxy A3
Samsung Galaxy A3 (2016)
Samsung Galaxy A3 (2017)
Samsung Galaxy A5 (2016)
Samsung Galaxy A5 (2017)
Samsung Galaxy A7 (2016)
Samsung Galaxy A7 (2017)
Samsung Galaxy A7 (2018)
Samsung Galaxy Ace 2
Samsung Galaxy Ace 4 LTE
Samsung Galaxy Ace Style
Samsung Galaxy Alpha
Samsung Galaxy Avant
Samsung Galaxy Axiom/Samsung Galaxy Admire 2
Samsung Galaxy C7
Samsung Galaxy C7 Pro
Samsung Galaxy C9 Pro
Samsung Galaxy Core 2
Samsung Galaxy Core Advance
Samsung Galaxy Core LTE
Samsung Galaxy Exhilarate
Samsung Galaxy Express
Samsung Galaxy Express 2
Samsung Galaxy Grand 2 LTE
Samsung Galaxy Grand Prime
Samsung Galaxy J5
Samsung Galaxy J7
Samsung Galaxy K Zoom
Samsung Galaxy Light
Samsung Galaxy Mega
Samsung Galaxy Mini 2
Samsung Galaxy Note
Samsung Galaxy Note 10/10+
Samsung Galaxy Note 3
Samsung Galaxy Note 4
Samsung Galaxy Note 5
Samsung Galaxy Note 8
Samsung Galaxy Note 9
Samsung Galaxy Note II
Samsung Galaxy Note20 Ultra
Samsung Galaxy Premier
Samsung Galaxy Round
Samsung Galaxy Rugby LTE/Pro
Samsung Galaxy S Advance
Samsung Galaxy S Blaze 4G
Samsung Galaxy S II
Samsung Galaxy S II Plus
Samsung Galaxy S III
Samsung Galaxy S III Mini
Samsung Galaxy S21, S21 Plus and S21 Ultra
Samsung Galaxy S22, S22+ and S22 Ultra
Samsung Galaxy S4
Samsung Galaxy S4 Active
Samsung Galaxy S4 Mini
Samsung Galaxy S4 Zoom
Samsung Galaxy S5
Samsung Galaxy S5 Active/Sport
Samsung Galaxy S5 Mini
Samsung Galaxy S6
Samsung Galaxy S6 Active
Samsung Galaxy S6 Edge
Samsung Galaxy S7
Samsung Galaxy S7 Edge
Samsung Galaxy S8
Samsung Galaxy S8 Plus
Samsung Galaxy Stratosphere II
Samsung Galaxy Victory 4G LTE
Samsung Galaxy Watch5 and Watch5 Pro
Samsung Galaxy XCover Pro
Samsung Galaxy Young
Samsung Galaxy Z Flip
Samsung Galaxy Z Flip4
Samsung Galaxy Z Fold3
Samsung Galaxy Z Fold4
Samsung S5230 NFC
Samsung S5260 NFC
Samsung SHW-A170K
Samsung Wave 578
Samsung Wave M
Samsung Wave Y
Samsung Windows RT Ativ Tablet
Samsung WP8 Ativ S
Sharp Aquos Phone Serie
Sharp Aquos Phone Zeta
Sharp RW-T107 NFC Tablet
Sharp RW-T110 NFC Tablet
Smartisan T2
Sonim XP1301 Core NFC
Sonim XPand NFC
Sony Digital Paper DPT-RP1
Sony SWR10 SmartBand
Sony Vaio Fit
Sony Xperia Acro S
Sony Xperia AX
Sony Xperia C5 Ultra
Sony Xperia E3 Dual
Sony Xperia Ion
Sony Xperia L
Sony Xperia M
Sony Xperia M2
Sony Xperia M5
Sony Xperia P
Sony Xperia S
Sony Xperia Sola
Sony Xperia SP
Sony Xperia T
Sony Xperia T2 Ultra
Sony Xperia Tablet Z
Sony Xperia V
Sony Xperia VL
Sony Xperia XZ Premium
Sony Xperia XZ1 Compact
Sony Xperia XZs
Sony Xperia Z
Sony Xperia Z Ultra
Sony Xperia Z1
Sony Xperia Z1 Compact
Sony Xperia Z2
Sony Xperia Z2 Tablet
Sony Xperia Z3
Sony Xperia Z3 Compact
Sony Xperia Z5
Sony Xperia ZL
Sony Xperia ZR
TazTag TazPad
TazTag TPH-One
The Toughphone Defender
THL 5000
Toughshield R-500
Toughshield T700
Turkcell MaxiPRO5
Turkcell T11/ZTE Racer II
Turkcell T40
Umi Cross
Umi X2S
Umidigi X
Vertu Constellation
Vertu Ti
Vodafone Smart 4 Power
Vodafone Smart 4 Turbo
Vodafone Smart III
Xiaomi Mi 2A
Xiaomi Mi 5 and Mi 5 Pro
Xiaomi Mi Mix
Xiaomi Mi Mix 2
Xiaomi Mi Note 2
Xiaomi Mi3
Xiaomi Poco X3 NFC
Xolo X900
Yota Devices YotaPhone (2014)
Yulong Coolpad 8870 NFC
Zopo ZP998
ZTE Axon
ZTE Blade II
ZTE Flash
ZTE GoTa GH800
ZTE Grand X IN
ZTE Kis
ZTE Nubia Z5
ZTE Orbit
ZTE PF200
ZTE R233
ZTE Turkcell MaxiPLUS5

[dkbit98]

You can find the list of compatible Android and iOS smartphones on the faq

I was not talking about smartphone models, but about actual version of Android operating system supported
Latest version of Android is 13, but is cryptoplatz supported for older Android OS 4 or 5?
Reason I ask this is because I have some ancient Android smartphone I could use for this purpose.

[n0nce]

And yes, you can do all operations offline, airplane mode for example (we recommend this on app)

Oh, that's a terrible idea of an 'offline computer'. Whatever device you use for any such endeavor, should be either booted off a live drive (CD or USB thumb drive) or destroyed / at least fully erased after the process, and before any radios are turned back on.
How do you think criminals attack your device? Do you think a short downtime erases any viruses or spyware? Keyloggers and screenloggers continue logging - whether you're connected to the internet or not, and just do the telemetry when network connection comes back.

It's a little bit disturbing that 'turning on airplane mode' is what springs to your mind when I talk about entering a seed phrase only on airgapped machines.

In my opinion, the app should not even exist and the NFC transceiver should come by default. You could provide a modified version of Tails with NFC drivers and your own software preinstalled; though do make sure that it's all open-source, with reproducible builds.

I'm slightly worried about the NFC device though: where you source it, whether it's trustable. Though I suppose if it's not plugged into anything other than the live-USB-booted computer, there's no way for it to do telemetry.

You need to decide what is better, leave your current seed only on paper or type the seed on CryptoPlatz App to save encrypted on the card, offline.

I'll be straight honest to you: Paper looks like the way better option here. Less fancy, but more simple and secure.

[cryptoplatz]

And yes, you can do all operations offline, airplane mode for example (we recommend this on app)

Oh, that's a terrible idea of an 'offline computer'. Whatever device you use for any such endeavor, should be either booted off a live drive (CD or USB thumb drive) or destroyed / at least fully erased after the process, and before any radios are turned back on.
How do you think criminals attack your device? Do you think a short downtime erases any viruses or spyware? Keyloggers and screenloggers continue logging - whether you're connected to the internet or not, and just do the telemetry when network connection comes back.

It's a little bit disturbing that 'turning on airplane mode' is what springs to your mind when I talk about entering a seed phrase only on airgapped machines.

In my opinion, the app should not even exist and the NFC transceiver should come by default. You could provide a modified version of Tails with NFC drivers and your own software preinstalled; though do make sure that it's all open-source, with reproducible builds.

I'm slightly worried about the NFC device though: where you source it, whether it's trustable. Though I suppose if it's not plugged into anything other than the live-USB-booted computer, there's no way for it to do telemetry.

You need to decide what is better, leave your current seed only on paper or type the seed on CryptoPlatz App to save encrypted on the card, offline.

I'll be straight honest to you: Paper looks like the way better option here. Less fancy, but more simple and secure.

Have you used before Ledger app, Trust wallet app, Exodus app? All of this apps you use online on iOS or Android, and this apps ask you to save the seed on paper.

The option that we are offering, is to save the seed encrypted and keep offline using open source app, with a industry standard chip NTAG424.

[cryptoplatz]

You can find the list of compatible Android and iOS smartphones on the faq

I was not talking about smartphone models, but about actual version of Android operating system supported
Latest version of Android is 13, but is cryptoplatz supported for older Android OS 4 or 5?
Reason I ask this is because I have some ancient Android smartphone I could use for this purpose.

Sorry, CryptoPlatz App is compatible with Android 4.1 and above

[n0nce]

Have you used before Ledger app, Trust wallet app, Exodus app? All of this apps you use online on iOS or Android, and this apps ask you to save the seed on paper.

The option that we are offering, is to save the seed encrypted and keep offline using open source app, with a industry standard chip NTAG424.

Okay, so this device then is only really suited to backup seed phrases of hot wallets; that makes sense. As the seed has already been exposed to an online device, it makes no difference whether you enter it in another app one more time. I guess.
Then the product is just not for me, and others who generate and back their seed phrases up without them touching an online device.

PS: Please take a look at:

Recently I noticed that a lot of new members don't know all the rules and I don't (usually) blame them since not all rules are written and even those written down can be overlooked by users who don't pay much attention to some stickies in select boards. Maybe they'll pay attention to this thread in which I'll try to list all the rules present on the forum. I'll provide sources (if I know of any) to where they are posted. The rules are in no particular order, just written as I found them although I'll try to keep the more general ones first.
[...]
32. Posting multiple posts in a row (excluding bumps and reserved posts by the thread starter) is not allowed.

[cryptoplatz]

Have you used before Ledger app, Trust wallet app, Exodus app? All of this apps you use online on iOS or Android, and this apps ask you to save the seed on paper.

The option that we are offering, is to save the seed encrypted and keep offline using open source app, with a industry standard chip NTAG424.

Okay, so this device then is only really suited to backup seed phrases of hot wallets; that makes sense. As the seed has already been exposed to an online device, it makes no difference whether you enter it in another app one more time. I guess.
Then the product is just not for me, and others who generate and back their seed phrases up without them touching an online device.

PS: Please take a look at:

Recently I noticed that a lot of new members don't know all the rules and I don't (usually) blame them since not all rules are written and even those written down can be overlooked by users who don't pay much attention to some stickies in select boards. Maybe they'll pay attention to this thread in which I'll try to list all the rules present on the forum. I'll provide sources (if I know of any) to where they are posted. The rules are in no particular order, just written as I found them although I'll try to keep the more general ones first.
[...]
32. Posting multiple posts in a row (excluding bumps and reserved posts by the thread starter) is not allowed.

When you use cold wallet devices, like Ledger and Trezor, the seed recovery phrase (12 words or 24 words) is "exposed" to an online device too, on mobile smartphone or computer.

[dkbit98]

When you use cold wallet devices, like Ledger and Trezor, the seed recovery phrase (12 words or 24 words) is "exposed" to an online device too, on mobile smartphone or computer.

No it's not exposed, and I can also connect hardware wallets to offline computer using Electrum wallet.
In ledger devices seed phrases are stored in secure element and it never leaves there, unless you reset your device.
Some hardware wallets like Passport, Keystone or ColdCard and air-gapped and they don't have cable connection with any devices.

[n0nce]

Have you used before Ledger app, Trust wallet app, Exodus app? All of this apps you use online on iOS or Android, and this apps ask you to save the seed on paper.

The option that we are offering, is to save the seed encrypted and keep offline using open source app, with a industry standard chip NTAG424.

Okay, so this device then is only really suited to backup seed phrases of hot wallets; that makes sense. As the seed has already been exposed to an online device, it makes no difference whether you enter it in another app one more time. I guess.
Then the product is just not for me, and others who generate and back their seed phrases up without them touching an online device.

PS: Please take a look at:

Recently I noticed that a lot of new members don't know all the rules and I don't (usually) blame them since not all rules are written and even those written down can be overlooked by users who don't pay much attention to some stickies in select boards. Maybe they'll pay attention to this thread in which I'll try to list all the rules present on the forum. I'll provide sources (if I know of any) to where they are posted. The rules are in no particular order, just written as I found them although I'll try to keep the more general ones first.
[...]
32. Posting multiple posts in a row (excluding bumps and reserved posts by the thread starter) is not allowed.

When you use cold wallet devices, like Ledger and Trezor, the seed recovery phrase (12 words or 24 words) is "exposed" to an online device too, on mobile smartphone or computer.

Absolutely not. Never. That's the whole idea of these devices. I'd stay clear of a company who creates 'Bitcoin security devices' of any type and believes a hardware wallet exposes its seed phrase to the host computer.