Substitution-Permutation Networks (SPNs) are a type of cryptographic algorithm that is used to secure data. They are often referred to as “confusion and diffusion” algorithms because they use both substitution and permutation techniques in order to achieve their security goals. SPNs use multiple rounds of encryption, each round consisting of two different operations: substitution and permutation.

The first operation, substitution, involves replacing plaintext with ciphertext by using a key or set of keys which can be changed according to the needs at hand. This process helps ensure that no patterns emerge from the encrypted data which could potentially lead an attacker back towards the original plaintext message or information being protected by it. The second operation is called permutation; this involves rearranging bits within blocks so that any patterns present in them become unrecognizable even if someone were able to decrypt some portion of it successfully through other means such as brute force attacks or dictionary attacks, etc.

Overall, these two operations combined create an effective form of cryptography since they make it extremely difficult for attackers who might have access only partway into your system’s security measures due to either luck or skillful attack methods from succeeding in obtaining sensitive information stored within them without having knowledge on how exactly all parts fit together perfectly like puzzle pieces do when put together correctly, but not otherwise when broken apart randomly instead.

As long as you keep changing up your keys regularly enough, then SPN should provide adequate protection against most forms of malicious hacking attempts out there today. Making them one viable option worth considering for those looking into implementing strong encryption protocols for their own systems’ and safety purposes.