Cryptography Developments: Elliptic Curves
I recently wrote about the NSA’s surprising announcement in August. They urged the community to work on post-quantum cryptography. More surprisingly, they also recommended that organizations that have not yet converted from traditional RSA-based public-key systems to the newer ECC (or Elliptic Curve Cryptography) should not bother doing so. RSA security relies on the difficulty […]
What Are Traffic Analysis and Metadata?
In Learning Tree’s System and Network Security Introduction we discuss “traffic analysis,” noting that even if data are encrypted, one can still find out information by looking at who is sending encrypted data to whom. Along that same line, there has been a lot of discussion in the press recently about “metadata” – information about […]
Keeping Secrets: Setting a Cipher Mode
Earlier this week we considered ways to split the many choices of ciphers (or encryption algorithms): symmetric versus asymmetric, and block versus stream. The block symmetric ciphers do the heavy lifting, they are used for large data sets. But one block symmetric cipher can be operated in various modes, and the selection of mode depends […]
Is “Perfect Forward Secrecy” Perfect?
My previous post was a response to a participant’s question — How Diffie-Hellman key exchange works? This time I’d like to talk about “Perfect Forward Secrecy” because some participants asked, “What makes it perfect?” Perfect Forward Secrecy or PFS is any scheme where discovering a key to access one message in an exchange between parties […]
Keeping Secrets: Select a Cipher
So you want to encrypt your sensitive information to protect its confidentiality. Good! But exactly how should this be done? There are many ciphers (or encryption algorithms) to choose from. Let’s see what choices are available. Splitting the Choices Selecting a cipher is like sharing bread with your friend. Wait. What? Let’s say you want […]