Small improvements

teschlg · Oct 23, 2024 · 07556ea · 07556ea
1 parent a0a695e
commit 07556ea
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Showing 4 changed files with 39 additions and 16 deletions.
diff --git a/doc/kryptools.ipynb b/doc/kryptools.ipynb
@@ -1088,7 +1088,7 @@
      "text": [
       "Factoring: 340282366920938463463374607431768211457 (39 digits)\n",
       "Trial division found: []\n",
-      "Round 1\n",
+      "Round 1 (B1=5000)\n",
       "Factors found (ecm):  [59649589127497217, 5704689200685129054721]\n"
      ]
     },
@@ -1135,7 +1135,7 @@
     {
      "data": {
       "text/plain": [
-       "[3, 19, 1579]"
+       "[487, 1709]"
       ]
      },
      "execution_count": 35,
@@ -1146,7 +1146,7 @@
    "source": [
     "from kryptools.factor_fmt import factor_fermat\n",
     "\n",
-    "factor_fermat(90003)"
+    "factor_fermat(832283)"
    ]
   },
   {
@@ -1162,7 +1162,18 @@
    "execution_count": 36,
    "id": "39f76a97-1b88-4b95-aac7-bf403043d7b7",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "1709"
+      ]
+     },
+     "execution_count": 36,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
     "from kryptools.factor_pm1 import factor_pm1\n",
     "\n",

diff --git a/kryptools/factor.py b/kryptools/factor.py
@@ -107,14 +107,19 @@ def add_factors(m: int, mm: tuple) -> None:
     fermat_steps = 10
 
     for round, parameters in enumerate(ECM_PARAMETERS):
-        if verbose:
-            print(f"Round {round+1}")
         fermat_steps += 10
         B1, B2, num_curves = parameters
+        p_max = isqrt(max(remaining_factors))+1
+        B1 = min(B1, p_max//50)
+        B2 = min(B2, p_max)
         num_curves *= 2
         D = isqrt(B2)
+
+        if verbose:
+            print(f"Round {round+1} (B1={B1})")
+
         primes = sieve_eratosthenes(B1 - 1 + ((B2 - B1 + 1) // (2 * D) + 1) * 2 * D)
-        pm1_parameters = _pm1_parameters(10 * B1, B2, primes = primes)
+        pm1_parameters = tuple([10 * B1, B2] + list(_pm1_parameters(10 * B1, B2, primes = primes)))
         ecm_parameters = tuple([B1, B2, num_curves] + list(_ecm_parameters(B1, B2, D, primes = primes)))
 
         methods = {_factor_fermat: "fmt", factor_pm1: "pm1", factor_ecm: "ecm"}  #, factor_qs: "qs"}

diff --git a/kryptools/factor_ecm.py b/kryptools/factor_ecm.py
@@ -93,7 +93,7 @@ def factor_ecm(n: int, B1: int|None = None, B2: int|None = None, curves: int = 1
         B1, B2, curves, D, stage_one, stage_two_deltas = ecm_parameters
     else:
         if not B1:
-            B1 = max(2, isqrt(n//200))
+            B1 = min(1000_000, isqrt(n)//200 + 2)
         if not B2:
             B2 = 100 * B1
         D, stage_one, stage_two_deltas = _ecm_parameters(B1, B2)
@@ -159,7 +159,7 @@ def factor_ecm(n: int, B1: int|None = None, B2: int|None = None, curves: int = 1
                     break
             if g == 0:
                 break
-            g =gcd(g,n)
+            g = gcd(g,n)
             if 1 < g:
                 if verbose > 1:
                     print("\nFactor found.")
@@ -171,6 +171,7 @@ def factor_ecm(n: int, B1: int|None = None, B2: int|None = None, curves: int = 1
             if verbose > 1:
                 print("\nFactor found.")
             return g
+
     if verbose > 1:
         print(f"\nNo factor after trying {curves} curves.")
 
diff --git a/kryptools/factor_pm1.py b/kryptools/factor_pm1.py
@@ -2,7 +2,7 @@
 Integer factorization: Pollard's p-1 method
 """
 
-from math import gcd, log, floor, log10
+from math import gcd, log, isqrt, floor, log10
 from .primes import sieve_eratosthenes
 
 def _pm1_parameters(B1: int, B2: int|None = None, primes: tuple = None):
@@ -27,24 +27,30 @@ def _pm1_parameters(B1: int, B2: int|None = None, primes: tuple = None):
     return stage_one, stage_two_deltas
 
 
-def factor_pm1(n: int, B1: int = 10000, B2: int|None = None, x: int = 2, pm1_parameters: tuple = None, verbose: int = 0):
-    "Factors a number n using Pollard's p-1 method."    
-    if verbose:
-        print(f"Factoring (Pollard p-1, B1={B1}, B2={B2}): {n} ({floor(log10(n)) + 1} digits)")
-
+def factor_pm1(n: int, B1: int|None = None, B2: int|None = None, x: int = 2, pm1_parameters: tuple = None, verbose: int = 0):
+    "Factors a number n using Pollard's p-1 method."
     if pm1_parameters:
-        stage_one, stage_two_deltas = pm1_parameters
+        B1, B2, stage_one, stage_two_deltas = pm1_parameters
     else:
+        if not B1:
+            B1 = min(1000_000, isqrt(n)//50 + 2)
         stage_one, stage_two_deltas = _pm1_parameters(B1, B2)
 
+    if verbose:
+        print(f"Factoring (Pollard p-1, B1={B1}, B2={B2}): {n} ({floor(log10(n)) + 1} digits)")
+
     # stage one
     if verbose > 1:
         print("Working 1", end= "")
     x = pow(x, stage_one, n)
     g = gcd(x - 1, n)
     if g == n:
+        if verbose > 1:
+            print("")
         return None
     if 1 < g:
+        if verbose > 1:
+            print("\nFactor found.")
         return g
 
     if verbose > 1: