301 reputation
112
bio website
location Paris, France
age
visits member for 2 years, 5 months
seen Dec 3 at 16:50

I'm an engineer with experience in applied cryptography, in particular in Smart Card systems.


Dec
1
comment Monstrous Diophantine Equation
A gremlin crept in this accepted answer's algebra! $x^6-y^6+3x^4y-3y^4x+3x^2+3x+1=0$ IS NOT equivalent to $(x+1)^3+(x^2+y)^3=(x+y^2)^3$. $\;$ Proof: $x=-1$, $y=-1$ is a solution of the later, but not of the former. $\;$ Other proof: mechanically expand $(x+1)^3+(x^2+y)^3-(x+y^2)^3$, giving $x^6-y^6+3x^4y-3y^4x+3x^2+3x+y^3+1$, with that pesky $y^3$ term.
Sep
24
awarded  Autobiographer
Jul
8
accepted Exists a binary primitive pentanomial of degree $n$, for every $n\ge5$?
Jul
7
comment Exists a binary primitive pentanomial of degree $n$, for every $n\ge5$?
Just to make it clear: that was me, about 4 years ago. I asked again because math.SE is perfect for this purpose, and there might have been progress/extra info.
Jul
4
revised Exists a binary primitive pentanomial of degree $n$, for every $n\ge5$?
add a line break
Jul
4
asked Exists a binary primitive pentanomial of degree $n$, for every $n\ge5$?
Jul
2
awarded  Curious
Apr
12
comment Enquiry to network flow
@AlexyVincenzo: No with that constraint that $(2,5),(4,5),(6,5),(6,7)$ are saturated. Yes without that constraint (we can reduce everything in proportion $8/14$).
Apr
12
revised Enquiry to network flow
Final polish.
Apr
12
revised Enquiry to network flow
This flow is maximal
Apr
12
revised Enquiry to network flow
Polish
Apr
12
comment Enquiry to network flow
@MJD: We have $(5,7)\le9$, because that's a given. I used $(5,7)←8$ to mean than $(5,7)$ is assigned the value $8$ in the flow, and that matches $8\le9$.
Apr
12
revised Enquiry to network flow
Polish
Apr
12
answered Enquiry to network flow
Apr
7
comment Find the area of quadrilateral formed by $4$ (not consecutive) vertices of a $12$-gon inscribed in a circle.
+1 for the idea of computing the area as ${d_1d_2\over2}\sin\theta$ and getting the details right!
Apr
5
revised Find the area of quadrilateral formed by $4$ (not consecutive) vertices of a $12$-gon inscribed in a circle.
Final polish
Apr
5
revised Find the area of quadrilateral formed by $4$ (not consecutive) vertices of a $12$-gon inscribed in a circle.
deleted 1 characters in body
Apr
5
revised Find the area of quadrilateral formed by $4$ (not consecutive) vertices of a $12$-gon inscribed in a circle.
Add figure
Apr
5
answered Find the area of quadrilateral formed by $4$ (not consecutive) vertices of a $12$-gon inscribed in a circle.
Apr
4
revised How many commutative block ciphers are there?
Some progress