67 reputation
210
bio website notyet;)
location Peacedale, RI
age
visits member for 2 years, 11 months
seen 5 hours ago

Electronics Engineer, Amateur Cryptographer with interests in designing real random and psuedorandom bit generators.

"Randomness is like a box of chocolates; you never know what you are going to get"

                                                                   Forrest Gump Jr.

"You can't use mathematical means to create true randomness but you can use mathematical means to stretch a short truly random bitstream into a binary string of virtually infinite length that is indistinguishable from the uniform distribution, the distinguisher being a Universal Turing Machine". John Von Neumann Jr.

"It's trivial to make a Turing machine that fools all other Turing machines into "thinking" that they are looking at an unpredictable uniform distribution. Here is the schematic."

                                                                   Alan Turing Jr.

12h
comment Secure way to store fixed size string of digits
@Brad W: If you can't baby-sit the memory stick without the chance of losing it or having someone pick your pocket, you have no business doing cryptography in the 21st century. Take up a more benign hobby. As to using the string as an identifier in a data base, you should configure your system so that it can't work until the information from the memory stick is entered.
1d
comment Secure way to store fixed size string of digits
Store the information on a memory stick and keep the stick in your pocket until you need to enter it into your system.
Jul
10
awarded  Notable Question
Jul
2
awarded  Curious
May
2
awarded  Benefactor
Apr
26
accepted Nonlinearity of the J-K Flip Flop
Apr
26
comment Nonlinearity of the J-K Flip Flop
@grieu, Nice work, answer accepted. You are the "hardest working man in cryptography !
Apr
26
comment Nonlinearity of the J-K Flip Flop
@DW , Yes I am aware of how hard it is, but I like the challenge. But now that I am retired, its either design something new or watch "Gilligan's Island" re-runs. Oh, and by the way, if I were you, I wouldn't bet against me ;-)
Apr
25
comment Nonlinearity of the J-K Flip Flop
So let me ask this question: if the J-K flip flop was correlation-immune, it could be considered a strong cryptographic combining function?
Apr
25
comment Nonlinearity of the J-K Flip Flop
OK < thanks for the info, this is interesting. According to some papers I've read bent functions have to have an even number of variables, so according to your analysis, the flip flop can't have the same nonlinearity as the bent functions. I will wait for more answers here, hopefully someone will enlighten us.
Apr
24
awarded  Promoter
Apr
22
asked Nonlinearity of the J-K Flip Flop
Apr
9
comment Convert m-Sequence into a de Bruijn Sequence
Thank you fgrieu but I am only interested in designing my own CSPRNG. I only study other designs to see what makes them strong (or fail !). It the reason I took up cryptography as a hobby. :-D
Apr
8
comment Convert m-Sequence into a de Bruijn Sequence
How about another solution? Make a generator consisting of three LFSR's , the outputs of which are XOR'd together , but each LFSR has its own LFSR as a random clock. Sure you will make the key length greater but the added clocking complexity will make attacks like the edit distance attack computationally infeasible. Who knows, maybe some clever mathematician will show that breaking this generator is NP Complete by showing a reduction to 3-SAT. ;-)
Apr
8
comment Convert m-Sequence into a de Bruijn Sequence
A feedback function with a 62 input NOR gate is going to be way too slow for my purposes :-(
Apr
8
comment Convert m-Sequence into a de Bruijn Sequence
Wow, how did you find this? You are fast!!!
Apr
8
accepted Convert m-Sequence into a de Bruijn Sequence
Apr
8
comment Convert m-Sequence into a de Bruijn Sequence
Just what I was looking for, you are the best. Not sure what "adding an XOR term equal to the NOR of the outputs of the n-1 flip flops" means??? Say I have a 63 bit register, for an m-sequence I will be tapping tap locations 62 and 63 with a single XOR gate for my feedback function. What am I adding to this to get the de Bruijn sequence?
Apr
8
comment Convert m-Sequence into a de Bruijn Sequence
Nice work but this not show me the electronic real-world circuit for inserting the zeros in the right places! You can't make an actual ASG without a schematic :-(
Apr
8
comment Convert m-Sequence into a de Bruijn Sequence
I don't understand why Gunther says in the paper "it is easy to convert an m-sequence into a deBruijn sequence. To me easy means simple. If you read some of the papers on generating deBruijn sequences, the syntheses are very complicated!!