Java Security Overview introduces you to cryptography, public key infrastructure, authentication, secure communication, access control, and XML signatures.
Security Architecture in the JDK 8 documentation provides an overview of the motivation of major security features, an introduction to security classes and their usage, a discussion of the impact of the security architecture on code, and thoughts on writing security-sensitive code.
Java Security Standard Algorithm Names Specification describes the set of standard names for algorithms, certificate and keystore types that Java SE requires and uses.
Permissions in the Java Development Kit (JDK) describes the built-in JDK permission types and discusses the risks of granting each permission.
Troubleshooting Security lists options for the java.security.debug system property that enable you to monitor security access.