Hi!

I have a problem with some algo. I included its pseudo code below. It's something like PowerMod but not exactly. It's used in public key cryptography. Does anyone know what's this? The algorithm operate on m,e,n and e is like in RSA e=65537. I do calculation for a few first e.

e=1: [m] mod n
e=2: [m^2-2] mod n
e=3: [m^3-3m] mod n
e=4: [m^4-4m^2+2] mod n
e=5: [m^5-5m^3-5m] mod n
e=6: [m^6-6m^4+9m^2-2] mod n
e=7: [m^7-7m^5+14m^3-7m] mod n

This is an algorithm:

In: M,N,E

R=M mod N
A=2
B=R

for(bit=BitCount(E)-1; bit>=0; bit--)
{
if(BitSet(E,bit)) // if bit=1
{
A=[(N-R)+(A*B)] mod N
B=[(N-2)+B^2] mod N
}
else // if bit=0
{
B=[(N-R)+(A*B)] mod N
A=[(N-2)+A^2] mod N
}
}

Out=A


Best regards,
Ajron.

ps. sorry for my english

Hi,

This is a LUC public key encryption scheme.
Here there are some links regarding it http://www.kisa.or.kr/technology/sub1/LUC.htm

Regards, Dimedrol.

Thx a lot

Best regards,
Ajron.