CryptoQR Application.
- create offline wallet addresses for various crypto coins
- print the wallet addresses in QR format
- decode printed QR images via a webcam
Download: https://github.com/cryptoqr/cryptoqr/releases
Initially you select the webcam to be used for decoding QR codes. From the selecton box you choose the crypto coin to be used. Then you have the following options
- generate 5 addresses --> this will generate 5 new wallet addresses.
- generate specific address --> this will try and generate an address containing a pattern. The pattern follows regular expressions (see http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html). for example the pattern. .*BTC.* will generate an address containing the characters BTC somewhere in the address and 1BTC.* will generate an address starting with 1BTC .
After generating addresses, you can click the "Print Last Generated" button which will print directly to the printer the last generated address(es).
At any time, show a QR code to the webcam and it will decode it. It will keep it in the clipboard so that you can paste it and optionally it will automatically paste it for you in the focused window if you have selected the "auto past QR code" checkbox. This is useful if you are in the wallet debug console as it will automatically paste the private key for you in order not to lose time.
To compile you will need:
- JDK 1.7 or higher
- Ant version 1.8 or higher
Download the source code ant type
ant -f buildProject.xml
this command will:
- compile
- create javadocs
- create the runtime distribution .zip file in the folder dist
To run the application you will need
- JDK 1.7
unzip the distribution and double click the .bat or .sh file to start the application.
in folder resources edit the file cryptoqr.properties
this file contains the necessary information to create addresses for various crypto coins and is configurable.
each coin configuration is separated with the "|" character and each coin parameter within the coin configuration is separated with the "," character. The format for the coin parameters is: ,,,
For example : BTC,00,80,secp256k1|LTC,30,B0,secp256k1
will configure 2 coins: BTC
- public key version number = 0x00
- private key version number = 0x80
- EC curve = secp256k1
LTC
- public key version number = 0x30
- private key version number = 0xB0
- EC curve = secp256k1
You can find these parameters in the source code of each coin, usually in file Base58.h
- class CBase58Data , PUBKEY_ADDRESS
- class CBitcoinSecret , PRIVKEY_ADDRESS or
chainparams.cpp
- base58Prefixes[PUBKEY_ADDRESS]
- base58Prefixes[SECRET_KEY]
Important note: the addresses generated follow the bitcoin algorithm. https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses
The coin EC curve should be by default secp256k1 as this is the curve that (all?) coins following the bitcoin address generation algotithm follow. However the software is configurable for potential future coins that will use different EC curves.