This post is fairly straightforward: to remind everyone that with cryptocurrency you are responsible for your own wallet, private keys, balances, and transactions. Nothing is reversible by the SmartCash team and it is entirely up to you to decide what to do with it.
This is not intended to be a comprehensive guide on what to do. There are a lot of issues related to security and threats that are not really addressed. Basically, this is intended to give you some ideas of what possibilities are available for you.
Generally, I recommend that nobody hold more than $1,000 in any one wallet or private key address. It's too much risk in one place.
There are stories of "investors" losing millions of dollars on an exchange due to their account being hacked. Shocking, but true, and such a poor regard for the value and responsibility of ownership.
There are also stories of lost hard drives, sold laptops, or misplaced keys. It happens and is pretty easy to do. In fact, you're not really a crypto veteran until you've experienced it to some level. It's incredibly easy to do if you don't think about things, are busy, or don't expect it to become valuable.
This is decent reading if you'd like a tea break: http://fortune.com/2017/11/25/lost-bitcoins/
Satoshi Nakamoto is estimated to once have had control of over 1 Million Bitcoins. They have never been spent. They may never be spent. If they are spent, it will be a huge day in the history of cryptocurrency.
A historical look:
This is a serious matter too as it's a paradigm shift of the deferred responsibility of other systems, where someone can regain you access. This is because it is decentralized and the design of blockchain puts the control on of the cryptocurrency soley on the users of the systems rather than the system administrators (in a way, there aren't any because of the consensus methods, too).
This is profoundly secure, and at the same time, shows how fragile it can be.
There is always the threat of other people with a hammer/gun/kidnapping/etc. It's a balance though, so you want enough security and backups so you don't actually throw away a hard drive and lose everything, but not so much that your family can't gain access to your crypto wealth should you die. However, you also need to take into account what could happen under duress. Your account isn't insured so the law enforcement folks probably won't be able to cover your loss. Same thing with insurance, most won't cover any loss... while they may if you were held at gunpoint and forced to give up something valuable like jewelry. These are issues that will likely be addressed in the future as more insurance companies, vault companies, and the like provide these sorts of services.
Let's break this down into two sections: Basic Backups and Advanced / Paranoid Security Techniques.
Remember: Keys always come in pairs. There is a public key and a private key. The public key is one you share to receive coins. The private key is one you keep secret to spend coins. Never share your private key! The SmartCash wallet also requires you to make a new backup when you create a new address, so remember to do that.
The basic idea is that you don't ever want to lose either your wallet.dat or your private key. These allow you to spend your SmartCash. Wallet.dat is a small file on your computer. Your private key is a short set of characters. They're not very large but they need to be inaccessible to others while accessible to yourself (if you really need it). A good rule of thumb for backups is to keep at least two backups on two types of media and at least in two different locations. That way in case of fire, flood, backup failure or other loss there is another backup waiting for you.
Generally you will want to encrypt your wallet. This will then require a passphrase to unlock it and use the private key. This is a good additional layer of security, and use a good password. Then also store the password in a safe place.
You can also export your private keys and save those.
On the desktop wallet:
On the mobile wallet there is also an option to export the private keys.
If you ever have a corrupt wallet.data you can try to recover the private keys with:
"smartcash-qt.exe -salvagewallet" from command prompt.
Couple places you can back things up:
USB DRIVE: Copy wallet.dat to a thumb drive so you can copy it back later if you need it.
CD: You can even get an archival quality CD to back things up. Maybe less easy to fail than a USB drive.
METAL WALLET: Things like billfodl allow you to create a private key with tiny metal scrabble tiles that are durable and won't burn like a paper wallet. This is probably the most secure possible in the sense that you won't have any data loss, and it's an offline format. Highly recommended you get this and store it safely. The private key is all you need to access funds.
Paper wallet: You can also just print your private key. However, some people get paranoid about sending anything by network printer as it could be compromised. Maybe not the best idea, but you could do it from a computer that is not connected to the internet and booting from Ninjastik.
Photo wallet: Take a picture of your private key on something like a Kodak Instant Print camera and store safely.
Hardware wallet (soon for SmartCash hopefully): Trezor, Ledger, Cool Wallet S
Now you need to keep these safe, waterproof, fireproof, theft proof, etc.
Advanced techniques:
Airgapped paper wallet creation: There are more advanced techniques involving the creation of a public/private keypair on an airgapped computer using the paper wallet generator. This is useful to create as savings account that you never want to spend from as you can be sure the private key is never compromised. This is sort of what a private key ceremony will do that underlys ZK-Snark based systems. You can do this on a computer not connected to the internet on a secure OS, such as one available to boot from a USB drive called Ninjastik. The keypair that is used creates a valid pair that would work on the blockchain. You never need to share that private key on any system someone could use it. With Ninjastik, you could also encrypt the disk with a strong password. Then just save the private key as a text file if on the secure OS (Lubuntu).
Ninjastik: This is an encrypted OS on an encrypted drive with built in tools. You can use it to make a paper wallet or in the future you can load the Electrum wallet on it. Boots up on pretty much any modern computer. Useful for travel and also to ensure you aren't using an insecure OS like Windows/Mac.
Veracrypt: This is a why to create a mountable disk image to store multiple wallet.dat files, passphrases, etc behind a password. You can create the disk image to be 300MB, which would allow it to store many wallet.dat files and also give you a chance to add redundacy to data loss using parity files (next bullet). You can then burn it to a CD with the parity files, add it to a USB disk, or
Parity Files: This is a technique against data corruption. A parchive is just a way to find and remove errors using fancy matrix math. You can use QuickPar to create these files which are useful to protect against data loss and repair a corrupted file. Useful to use directly with wallet.dat files but probably just easier to use with the Veracrypt image file
Split apart your private key: This is similar to what Coinbase does (according to their SEC filings). They split apart the private key so it can only be constructed when each is recombined. This helps in case one area is compromised you don't lose everything. You could split it into keys held in different continents. It would take some time to put it all back together, a bit like a puzzle.
Remember, always use a secure passphrase! Never store that in email. Never store that on your desktop, or in "my documents". Always use a virus scanner, and if you can use a dedicated computer for interacting with crypto and especially consider Ninjastik!
One more thing you can do is use the CryptoNite by Metacert protocol plugin on chrome. It will verify SmartCash.cc and wallet.smartcash.cc to make sure they are correct and show you a green shield: https://chrome.google.com/webstore/detail/cryptonite-by-metacert/keghdcpemohlojlglbiegihkljkgnige?hl=en.
And always be paranoid and double check you backed stuff up! It also helps to have a legacy plan in place for your sudden demise. You may also want to come up with a plan for if you get into a "heist" situation. Generally, I suggest you don't hold more than minimal amounts which you won't mind giving up in that situation and the rest can be with a secure location/custodian where you would have a code for a duress situation to alert authorities (or just diversify into things like education, paying off all loans, or land which are less subject to seizure).
