One of the base principles of cryptography is that you can't just encrypt multiple messages with the same key. At the very least, what will happen is that two messages that have identical plaintext will also have identical ciphertext, which is a dangerous leak. (This is similar to why you can't encrypt blocks with ECB.)
If you think about it, a pure encryption function is just like any other pure computer function: deterministic. Given the same set of inputs (key and message) it will always return the same output (the encrypted message). And we don't want an attacker to be able to tell that two encrypted messages came from the same plaintext.
The solution is the use of IVs (Initialization Vectors) or nonces (numbers used once). These are byte strings that are different for each encrypted message. They are the source of non-determinism that is needed to make duplicates indistinguishable. They are usually not secret, and distributed prepended to the ciphertext since they are necessary for decryption.
The distinction between IVs and nonces is controversial and not binary. Different encryption schemes require different properties to be secure: some just need them to never repeat, in which case we commonly Continue reading
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The company is targeting enterprise customers with the service.
The northern Syrian city of Aleppo is one of the key battlegrounds of that country’s on-going civil war as well as the epicenter of the European refugee crisis. The most appropriate United States response to events in Aleppo has become a major foreign policy question among the candidates in this year’s U.S. presidential election. Experts are now predicting that forces loyal to President Bashar al-Assad, backed by the Russian military, will take control of rebel-held eastern Aleppo within weeks. The image below (from Wikipedia) illustrates the the current state (as of 9 October 2016) of the conflict in Aleppo, depicting rebel-held regions in green and those under government control in red.
From a BGP routing standpoint, this development was reflected by the disappearance of AS24814 — we first reported the appearance of AS24814 serving Aleppo in 2013. At 14:42 Continue reading
THE HAGUE, Netherlands — Nuage Networks has landed its biggest customer yet for software-defined wide-area networking (SD-WAN), as BT plans to offer the service to its enterprise customers globally. More specifically, BT has selected Nuage‘s Virtualized Network Services (VNS), which the vendor considers a superset of SD-WAN. The deal hasn’t been announced, but Neil McRae,... Read more →
Broadcom announced a new addition to their growing family of merchant silicon today. The new Broadcom Tomahawk II is a monster. It doubles the speed of it’s first-generation predecessor. It has 6.4 Tbps of aggregate throughout, divided up into 256 25Gbps ports that can be combined into 128 50Gbps or even 64 100Gbps ports. That’s fast no matter how you slice it.
Broadcom is aiming to push these switches into niches like High-Performance Computing (HPC) and massive data centers doing big data/analytics or video processing to start. The use cases for 25/50Gbps haven’t really changed. What Broadcom is delivering now is port density. I fully expect to see top-of-rack (ToR) switches running 25Gbps down to the servers with new add-in cards connected to 50Gbps uplinks that deliver them to the massive new Tomahawk II switches running in the spine or end-of-row (EoR) configuration for east-west traffic disbursement.
Another curious fact of the Tomahawk II is the complete lack of 40Gbps support. Granted, the support was only paid lip service in the Tomahawk I. The real focus was on shifting to 25/50Gbps instead of the weird 10/40/100Gbps split we had in Trident II. I talked about this a couple of Continue reading
These open source tools can be invaluable aids for managing and troubleshooting networks.