Tag Archives: Programming

How to get a job with 70 lines of code

After my recent post How to get a job with 250 lines of code there is a new challenge available, cf. followthewhiterabbit: They kindly provide a list of words containing the building blocks of the solution as well as an “anagram … Continue reading

Posted in Hash functions, Programming | Tagged , , , , , | 3 Comments

Mocking Spring Data repositories

Unit testing should be a substantial part of the work of any developer. If you are using Spring Data, maybe in conjunction with Spring Boot, the time it takes to boot up a test environment can be quite substantial. For … Continue reading

Posted in Programming | Tagged , , , , , , | 1 Comment

TLS/SSL certificate exchange in Java

In today’s blog post, we will take a look on how to handle (somewhat self-signed) certificates in Java. 1. Example server using spring-boot Let’s set up a minimal spring-boot RESTful service. Basically a ‘Hello world’-type one. Nothing fancy, just for … Continue reading

Posted in Programming, Security, Security/Encryption | Tagged , , , , , | Leave a comment

How to get a job with 250 lines of code

Recently, I stumbled upon a cryptographic challenge posed by a company called “Trustpilot”. The problem was available at http://followthewhiterabbit.trustpilot.com/challenge2.html. For completeness I post a screenshot here: Let that sink for a little while. Generously, the key has only six unknowns, … Continue reading

Posted in Encryption, Programming, Security/Encryption | Tagged , , , , , | 1 Comment

Random Java objects for testing

As a Java developer you should test the code you’re writing. In a perfect world every line of code should be covered by a test scenario. But writing tests takes time and doesn’t add functionality to your product. To make … Continue reading

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The RC4 stream cipher

Today I will continue my crypto-101 series with the very popular stream cipher RC4 (Ron’s code 4 by Ronald L. Rivest). I want to say at the very beginning that RC4 is not regarded as secure anymore as by today’s … Continue reading

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