This is a supplementary guide for the simple blockchain from scratch Java tutorial series.
What is Bouncy Castle.
Bouncy Castle is a cryptographic API for Java, provided by a non-profit charity based in Australia. It provides a number of cool cryptographic tools, like allowing elliptic curve digital signatures…
Downloading BouncyCastle.
You will need to download Bouncy Castle Jar ( “bcprov-jdk15on-159.jar” ) from the website. As always, make sure to keep a note of where you saved it.
Creating a User Library for BouncyCastle.
Open Windows >preferences in the Eclipse menu, and navigate to the Java>Build path > User Libraries tab. Click new and enter a new User Library name: like “bouncycastle_lib” and hit ok. With “bouncycastle_lib” selected press Add External JARs and find the bcprov-jdk15on-159.jar (or what ever version you downloaded). Apply and Close.
Adding the User Library to a package.
Right click your package in package explorer > Build path > Add Libraries. Select User libraries and then press next, now just tick “bouncycastle_lib” and click finish.
Import it with import org.bouncycastle.*;
