This post will discuss AES 256 in Java. To achieve the desired key length of 256, the Java Cryptography Extension (JCE) must be installed. If you’d rather not worry about adding the files for the JCE, simply change keyLength in AESTest.java from 256 to 128 (the maximum limited strength key length).
Java is capable of unlimited strength cryptography, just not out of the box. As the README from the Java Cryptography Extension (JCE) states, “Due to import control restrictions of some countries, the version of the JCE policy files that are bundled in the Java Runtime Environment, or JRE(TM), 8 environment allow ‘strong’ but limited cryptography
Install Java Cryptography Extension Read More »
In this post, the second of two, we will discuss the re-implementation of all necessary classes to provide “internal” Java support for custom hashing. In all, five classes (java.util.HashMap, java.util.HashSet, java.util.AbstractMap, java.util.LinkedHashMap, and java.util.LinkedHashSet) must be handled. The benefit of this approach is minimal alterations to existing code. That is, instead of importing from java.util.HashMap,
Custom String Hashing – Part II Read More »
In this post, the first of two, we will discuss a workaround for providing custom String hashing. While this is not the most elegant solution, it does the job.
Custom String Hashing – Part I Read More »
In this post, I’m going to share my custom logging class. It can be seen as a scaled down version of log4j, which is a comprehensive logging application. While log4j is great, it is not easily added to ones program. I’ve used log4j before and found it very helpful in large applications, but when I’m
When gathering statistics on a set of values, min and max are natural inclusions. Both are simple to locate by iterating over the set of values, performing \(n-1\) (where \(n\) is the size of the set) comparisons. Locating both seems trivial – perform each for a total cost of \(2n\). However, there is a more
Simultaneous min/max Read More »
JNI stands for Java Native Interface (detailed Oracle documentation). It allows Java to execute code written in other languages such as C/C++ and assembly. So, why would you want to do this? While Java is quite comprehensive, it is by design generic. That is, it must operate seamlessly across all supported architectures (and there are
This post discusses the basics of using JDBC (Java Database Connectivity) to interface Java with a JDBC-enabled database. Here, PostrgreSQL will be said database. To follow along with this tutorial, you’ll need to download PostgreSQL and its JDBC driver, create a new Java project in your IDE, and add the JDBC jar to its library
JDBC – a PostgreSQL example Read More »
A quick Google search for Java combination generators produces many results; nearly all focus on recursion (for more on recursion, see this post). While suitable for smaller sets, deep recursion quickly saturates the recursive stack, crashing Java. Thus, an iterative approach is warranted. In this post, both recursive and iterative approaches are shown.
Recursion is a programming technique that deconstructs a large process into a series of small, identical steps. Thus, a single method is created that continually calls itself to solve the next iteration by altering the parameters. This continues until some termination criterion is reached. While recursion is a useful tool, it requires additional memory to
