5
votes
2answers
214 views

Is my id obfuscation algorithm secure?

I'm designing an id obfuscation system. My system includes: Embedded chips, each chip has a unique 32-bit address (id). Server Insecure low-bandwidth unstable one-way channels from the chips to the ...
4
votes
2answers
99 views

Is it possible to construct a secure block cipher of size $2n$ given a secure block cipher of size $n$?

Given, say, the Blowfish block cipher, which is considered secure but only has a 64-bit block size, can we construct a secure block cipher of 128-bit block size? Say we run the key through two KDFs, ...
6
votes
3answers
4k views

Is Blowfish strong enough for VPN encryption?

I'm looking at an OpenVPN connection between two sites configured to use 128 bit Blowfish in CBC mode, and trying to figure out how to assess the strength, but I just don't know enough of the maths. ...