MAGNUS

MAGNUS was the codename for a UNSC cryptographic system for encrypting UNSC signals. Initially developed by a specialist team in the Spartan Corps in response to grievous breaches of existing systems, its success saw wider distribution to the UNSC, and eventually to allies. 
==Design== 
Proper encryption is handled by the MAGNUS software, creating encryption patterns using computational complexity that not only scrambles the message with hard problems, but also the size of the message, and the message order. Even if an element of the encryption is broken, the message padding, and scrambling of its order make it further difficult to determine the message nature. It uses three levels of cascading encryption to further protect the message, creating deeper levels of encryption. Finally, to prevent ease of access, MAGNUS uses an asymmetric encryption technique, where only the sender has the appropriate encryption key, and receiver uses a different decryption key, ones generated by MAGNUS for that single message. MAGNUS uses individual logins that rotate on a daily basis, meaning if access is gained to MAGNUS one day, it is lost the following day. 
MAGNUS's complexity means that, as of yet, it has not been breached, with super computing attempts only getting as deep as one layer of encryption. Brute force attacks are confounded by self-adjusting encryption, and thanks to software protection on MAGNUS, no copy of the program has been successfully retrieved. 
==History== 
MAGNUS was developed by a group of electronic and cyber warfare specialists in the Spartan Corps in response to the catastrophic breach of ONI's ISHTAR encryption system. Despite clear knowledge that ISHTAR was breached, and vulnerable, ONI continued to use it, created a new encryption layer that did not resolve the issue of the original breach, and only delayed further attempts to decrypt it's content. MAGNUS was developed in the span of two months, and operational for a month following that. The system underwent significant and rigorous testing, using Blackjack Company for adversarial testing, launching blunt force attacks, advanced penetration tests, and even engaging in "red team" testing to secure access to it through direct action, failing in all regards. No backdoors, or vulnerabilities were discovered through testing, and while a MAGNUS encryption system was operational between a FTL comms beacon on Acrturus and Midgard, even an attack by an AI triumvirate from Project Erinyes failed to gain any significant traction in breaching it. MAGNUS was accepted as the secondary encryption system of the Spartan Corps, behind ISHTAR, as used by ONI, and QUEEN, as used by UNICOM and NAVCOM. 
Despite introductions of MAGNUS to the UNSC at large, there was little interest. The efforts at re-securing ISHTAR were considered successful, and the matter was left. However, during the humiliating Demiurge War, the failures of ISHTAR and QUEEN were plain to see, with UNSC operational planning completely breached. In fact, of the ill-fated Task Force Tiamat, the only surviving vessel was the UNSC Eidolon, which ceased use of ISHTAR and QUEEN, and began using MAGNUS mid-way through the engagement. 
Following this, MAGNUS was deployed en-masse to the UNSC as quickly as allowed, and updated MAGNUS versions were created for specialist tasks, with MAGNUS ULTRA using a symmetrical encryption key for localised communications, and MAGNUS ASTRA being used for Quantum communications. MAGNUS also partially replaced the SOS encryption system Nemet, a collection of Covenant-era encryption systems used by the Justiciars. Following gross failings, it was largely replaced by Kalig, which used elements of MAGNUS, though MAGNUS was also used. A further refinement, MAGNUS FERRUS, was utilised by UNSC allies in the Frontier Coalition, Freeholds, and Warbound. It too used a symmetrical encryption key, but was designed in such a way that if breached, it would not compromise the UNSC's own MAGNUS. 
==Use==
MAGNUS replaced multiple encryption systems in the UNSC to create one unified, unbreakable code that allowed UNSC communiques to be transmitted without fear of encryption. Despite heavy enemy activity in attempting to break the code, secure keys, or an accessible version of MAGNUS, it remains unbroken.