1
vote
2answers
102 views

What are the major flaws and limitations of this hash-based stream cipher design?

K is a 224-bit key. C is a 32-bit counter; it is publicly known. the same value is never used twice. ...
2
votes
1answer
128 views

Building a stream-cipher out of a hash function?

I've already read this: Is it feasible to build a stream cipher from a cryptographic hash function? However, my proposed construction differs… Suppose the hash generates N bits. These bits are split ...
1
vote
2answers
243 views

Can I construct a feasible stream cipher out of HMAC and a secure hash algorithm?

I have constructed a stream cipher from a secure hash algorithm and a HMAC. Here is a brief description of the algorithm: Let: (Actually Objective-C styled pseudo code) ...
4
votes
2answers
164 views

Stream cipher with Diffie-Hellman and Cryptographic Hash Function?

(Already asked the same question on stackoverflow but I was told to better ask here. http://stackoverflow.com/questions/17527192/one-time-pad-with-dh-and-cryptographic-hash-function) I know: Never do ...
11
votes
4answers
772 views

Can you make a hash out of a stream cipher?

A comment on another question made me wonder about something: Assume you're on a rather constrained platform — say, a low-end embedded device — with no built-in crypto capabilities, ...
7
votes
4answers
1k views

Is it feasible to build a stream cipher from a cryptographic hash function?

A few years ago I devised a symmetric-key system that worked like so: ...