Question: Programmin Wu/Sun's Schema A with Maple

Hello,

I'm a bit lost, cause I Have to programm the "Schema A" from Wu/Sun with Maple. It's about Rebalanced-CRT-RSA, and therefore a key generation algorithm.

Unfortunately I havn't worked with Maple (or similar programms) yet. So if somebody will help me, that would be really kind :)

Here's the Algorithm (Source: Wu/Sun, Design of Rebalanced RSA-CRT for fast Encryption):

Step 1. Randomly select an odd number e of 568 bits.

Step 2. Randomly select a number kp1 of 160 bits, such that gcd(kp1, e) = 1.

Step 3. Based on Theorem 4.1, we can uniquely determine two numbers dp, k_{p1} < dp < 2k_{p1},
and P , e < P < 2e, satisfying ed_p = k_{p1}P + 1.
Step 4. Factor P as P = k_{p2} · p_0 such that k_{p2} is a number of 56 bits and p (= p_0 +1) is a prime
number. If this is infeasible, then go to Step 2.
Step 5. Randomly select a number k_{q1} of 160 bits, such that gcd(k_{q1}, e) = 1.
Step 6. Based on Theorem 4.1, we can uniquely determine two numbers dq, k_{q1} < d_q < 2k_{q1},
and Q, e < Q < 2e, satisfying ed_q = k_{q1}Q + 1.
Step 7. Factor Q as Q = k_{q2} · q_0 such that k_{q2} is a number of 56 bits and q (= q_0 +1) is a prime
number. If this is infeasible, then go to Step 5.
Step 8. The public key is (N, e); the secret key is (d_p, d_q, p, q).

Thank you for any help!

Edit2: I'm a fool, the integers arent of the right form, so they're not 568-bit/160-bitform :/

Edit:

I continued tryin, and I think i got at least Step 1-3:

Step 1+2: 

restart; 
with(RandomTools); 
BeidesGCD := proc () 
local a, b, A, B, C; 
global e, kp1; B := proc () 
b := Generate(nonnegint(range = 2^568)) 
end proc; 
while length(b) <> 171 do B() end do; 
while type(b, odd) = false do B() end do; 
A := proc () 
a := Generate(nonnegint(range = 2^160)) 
end proc; 
while length(a) <> 49 do A() end do; 
while gcd(a, b) <> 1 do A() end do; 
e := b; print(b); 
kp1 := a; 
print(a); 
gcd(e, kp1) 
end proc 

and the numbers needed for Step 3:

x := 1/e mod kp1; 
y := (e*x-1)/kp1; 

dp := x+kp1; 
P := y+e; 

But the next step causes problems, is it even possible to tell Maple "sth is infeasible"?