1 files changed, 21 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/PrimeCertaintyCalculator.java b/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/PrimeCertaintyCalculator.java
new file mode 100644
index 00000000..92431ef4
--- /dev/null
+++ b/bcprov/src/main/java/org/bouncycastle/jcajce/provider/asymmetric/util/PrimeCertaintyCalculator.java
@@ -0,0 +1,21 @@
+package org.bouncycastle.jcajce.provider.asymmetric.util;
+
+public class PrimeCertaintyCalculator
+{
+    private PrimeCertaintyCalculator()
+    {
+
+    }
+
+    /**
+     * Return the current wisdom on prime certainty requirements.
+     *
+     * @param keySizeInBits size of the key being generated.
+     * @return a certainty value.
+     */
+    public static int getDefaultCertainty(int keySizeInBits)
+    {
+        // Based on FIPS 186-4 Table C.1
+        return keySizeInBits <= 1024 ? 80 : (96 + 16 * ((keySizeInBits - 1) / 1024));
+    }
+}