Using tablets as bitcoin clients

[russL]

This post is a good candidate for RTFM comments. Identification the FM to read would be appreciated
On another post, I've asked about building a bitcoin miner using Udoo Quads. I'm sure that (eventually) that project can be setup to accept ssh logins in a secure manner. My provider is Verizon and I have a couple of ellipsis 7 tablets to use as remote clients. Having secured the server end, the problem is to secure the remote client. I can write Android apps and root the tablet if necessary. I do not trust the tablet or network to be secure.

Any help for the truly paranoid?

[infested999]

Search for an SSH Server on the Android Play Store.

[russL]

Search for an SSH Server on the Android Play Store.

That would work if I weren't so paranoid.
Things I do (and recommend to anyone where serious information or money is at risk):
a) Have at least one computer with no internet connection, and with only wired keyboard and mouse;
b) Build all apps that must be secure from source on the unconnected computer;
c) Create all keyrings on the unconnected computer;
d) Don't use an MS operating system for secure builds;
e) Transfer all data from the unconnected computer using only freshly partitioned and formatted media;
f) Only use media that has been subjected to a secure wipe.

BTW, don't use video card based mining hardware. Most video cards have been cracked. Some come from the factory with pre-installed viruses.
   

[infested999]

I wasn't able to give you much information because I couldn't understand your OP. Let me give it another try.

This post is a good candidate for RTFM comments. Identification the FM to read would be appreciated
On another post, I've asked about building a bitcoin miner using Udoo Quads. I'm sure that (eventually) that project can be setup to accept ssh logins in a secure manner. My provider is Verizon and I have a couple of ellipsis 7 tablets to use as remote clients. Having secured the server end, the problem is to secure the remote client. I can write Android apps and root the tablet if necessary. I do not trust the tablet or network to be secure.

Any help for the truly paranoid?

You have a couple of ellipsis 7 tablets (Mid-Range Verizon 4G tablets). You want to mine using Udoo Quads (Raspberry Pi style ARM PC). You want to login to [the Quads] using SSH with full security? Maybe over Verizon 4G (LTE)?

What is running Android? The Ellipsis 7 or the Quads?

[russL]

I wasn't able to give you much information because I couldn't understand your OP. Let me give it another try.

This post is a good candidate for RTFM comments. Identification the FM to read would be appreciated
On another post, I've asked about building a bitcoin miner using Udoo Quads. I'm sure that (eventually) that project can be setup to accept ssh logins in a secure manner. My provider is Verizon and I have a couple of ellipsis 7 tablets to use as remote clients. Having secured the server end, the problem is to secure the remote client. I can write Android apps and root the tablet if necessary. I do not trust the tablet or network to be secure.

Any help for the truly paranoid?

You have a couple of ellipsis 7 tablets (Mid-Range Verizon 4G tablets). You want to mine using Udoo Quads (Raspberry Pi style ARM PC). You want to login to [the Quads] using SSH with full security? Maybe over Verizon 4G (LTE)?

What is running Android? The Ellipsis 7 or the Quads?

Thanks for the response,

Basically correct.

The Quads are running Udoobuntu, a Ubuntu for ARM processors. The Ellipsis' run Android (as does a NOOK I have available). The Ellipsis will be used only as a client (i.e. to make or receive payments). The Udoo will be doing mining and serve the wallets.  SSH between the Ellipsis and the Udoo will be over either the 4g or a local hotspot.

The Udoo has 4 cores for the ARM and the equivalent of an Arduino UNO on board. I also have available several Raspberry Pi's and other computers to play with.

I would like to build the Android bitcoin wallet and ssh apps from scratch.

[infested999]

So you want to use the Ellipsis to input "Send X BTC to 1XXXXXXX". Then the Ellipsis will tell the Quads (which hold the Bitcoin wallets) "Hey, send X BTC to 1XXXXXX" over SSH. Then the Quads will actually send the Bitcoin. This all is then somehow more secure because the wallet is not stored on the active machine, but separately.

It is possible to write this program using SSH and bitcoind.

[russL]

So you want to use the Ellipsis to input "Send X BTC to 1XXXXXXX". Then the Ellipsis will tell the Quads (which hold the Bitcoin wallets) "Hey, send X BTC to 1XXXXXX" over SSH. Then the Quads will actually send the Bitcoin. This all is then somehow more secure because the wallet is not stored on the active machine, but separately.

It is possible to write this program using SSH and bitcoind.

Almost. If the wallet isn't on the active machine, it can't be lost or stolen. Also the secure keys could be stored separately, perhaps scanned as qr codes or loaded as needed via usb port. The tablet is essentially a dumb terminal. SSH would be configured to accept connections to the wallet only from devices with specific uuids.
I send a request for x amount of bitcoins, get back a qr code, the merchant scans the code, transaction is done.

At least I think that is what I'm reading about spending bitcoins.

[infested999]

I send a request for x amount of bitcoins, get back a qr code, the merchant scans the code, transaction is done.

What is contained in the QR code? It would be cool if a new wallet with new public+private keys is created with just enough BTC to serve that one transaction, then you give the merchant that wallet.

[Abdussamad]

This all is then somehow more secure because the wallet is not stored on the active machine, but separately.

Almost. If the wallet isn't on the active machine, it can't be lost or stolen.

What is the definition of active machine then? If the Udoo pc is doing mining then its connected to the Internet and very much an active machine.

SSH would be configured to accept connections to the wallet only from devices with specific uuids.

I have never heard of such an option. Where in sshd_config is there such an option?

I send a request for x amount of bitcoins, get back a qr code, the merchant scans the code, transaction is done.

It doesn't work like that. You have to specify the recipient's address and amount and it is bitcoind that will send the transaction over the network.

[russL]

This all is then somehow more secure because the wallet is not stored on the active machine, but separately.

Almost. If the wallet isn't on the active machine, it can't be lost or stolen.

What is the definition of active machine then? If the Udoo pc is doing mining then its connected to the Internet and very much an active machine.

The Udoo is the one doing the mining and has a its own wallet. I thought it was possible to set up a sort of bitcoin bank with multiple accounts (aka wallets) served from one central server. I have my account, my grandson has his account. Using a smartphone or some such, I would ssh into my account and request a transfer. I would get back something indicating the transfer has been entered.  From my first reading, I thought the immediate response would be either a "physical" bitcoin as an image or a verifiable conformation code. After all the vendor needs conformation before I take my coffee and leave 

SSH would be configured to accept connections to the wallet only from devices with specific uuids.

I have never heard of such an option. Where in sshd_config is there such an option?
[\quote}
My bad. I was referring to using MAC/SSID over a VPN to connect my remotes to the server. I tried to set up a system that forbid certain OS from connecting but didn't have much success.

I send a request for x amount of bitcoins, get back a qr code, the merchant scans the code, transaction is done.

It doesn't work like that. You have to specify the recipient's address and amount and it is bitcoind that will send the transaction over the network.

See my comment above. I understand the transaction has to be added to the block chain. I thought there was also the equivalent of a cash transaction accomplished by using "physical" bitcoins. I understand US regulators are concerned someone might offer some such service to the public and thus be in the business of printing money.