diff --git a/source/backend/parser/express.cpp b/source/backend/parser/express.cpp
index cd47faf..d32d632 100644
--- a/source/backend/parser/express.cpp
+++ b/source/backend/parser/express.cpp
@@ -1113,7 +1113,7 @@ void Parser::Parse_Num_Factor (EXPRESS Express,int *Terms)
 					i = (int)Parse_Float_Param();
 					if ((i < 0) || (i >= Number_Of_Random_Generators))
 						Error("Illegal random number generator.");
-					Val = stream_rand(i);
+					Val = stream_rand(&next_rand[i]);
 					break;
 
 				case DIMENSIONS_TOKEN:
@@ -3485,6 +3485,36 @@ void Parser::POV_strlwr(char *s)
 	}
 }
 
+#define ROTATE(v,c) (((v) << (c)) | ((v) >> (32 - (c))))
+#define XOR(v,w) ((v) ^ (w))
+#define PLUS(v,w) (((v) + (w)))
+#define PLUSONE(v) (PLUS((v),1))
+
+#define QUARTERROUND(a,b,c,d) \
+  x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]),16); \
+  x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]),12); \
+  x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]), 8); \
+  x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]), 7);
+
+void Parser::chacha(uint32_t *output32, uint32_t *input32)
+{
+  int i;
+  uint32_t x[16];
+
+  for (i = 0;i < 16;++i) x[i] = input32[i];
+  for (i = 8;i > 0;i -= 2) {
+    QUARTERROUND( 0, 4, 8,12)
+    QUARTERROUND( 1, 5, 9,13)
+    QUARTERROUND( 2, 6,10,14)
+    QUARTERROUND( 3, 7,11,15)
+    QUARTERROUND( 0, 5,10,15)
+    QUARTERROUND( 1, 6,11,12)
+    QUARTERROUND( 2, 7, 8,13)
+    QUARTERROUND( 3, 4, 9,14)
+  }
+  for (i = 0;i < 16;++i) x[i] = PLUS(x[i],input32[i]);
+  for (i = 0;i < 16;++i) output32[i] = x[i];
+}
 
 /*****************************************************************************
 *
@@ -3494,7 +3524,7 @@ void Parser::POV_strlwr(char *s)
 *
 * INPUT
 *
-*   stream - number of random stream
+*   stream - pointer to next_rand_t struct
 *
 * OUTPUT
 *
@@ -3517,11 +3547,15 @@ void Parser::POV_strlwr(char *s)
 *
 ******************************************************************************/
 
-DBL Parser::stream_rand(int stream)
+DBL Parser::stream_rand(next_rand_t *nr)
 {
-	next_rand[stream] = next_rand[stream] * 1812433253L + 12345L;
+	if (nr->nrints == 0) {
+		if (!++nr->in[12]) if (!++nr->in[13]) if (!++nr->in[14]) ++nr->in[15];
+		chacha(nr->out, nr->in);
+		nr->nrints = 16;
+	}
 
-	return((DBL)(next_rand[stream] & 0xFFFFFFFFUL) / 0xFFFFFFFFUL);
+	return((DBL)(nr->out[--nr->nrints]) * (DBL)0.00000000023283064365386962890625);
 }
 
 
@@ -3546,7 +3580,7 @@ DBL Parser::stream_rand(int stream)
 *
 * DESCRIPTION
 *
-*   Set start value for pseudo-random generator.
+*   Allocate a new generator and set start value for pseudo-random generator.
 *
 * CHANGES
 *
@@ -3556,12 +3590,31 @@ DBL Parser::stream_rand(int stream)
 
 int Parser::stream_seed(int seed)
 {
-	next_rand = (unsigned int *)POV_REALLOC(next_rand, (Number_Of_Random_Generators+1)*sizeof(unsigned int), "random number generator");
-
-	next_rand[Number_Of_Random_Generators] = (unsigned int)seed;
+	next_rand_t *nr;
+
+	next_rand = (next_rand_t*)POV_REALLOC(next_rand,
+		    (Number_Of_Random_Generators+1)*sizeof(next_rand_t),
+		    "random number generator");
+	nr = &next_rand[Number_Of_Random_Generators];
+	nr->nrints = 0;
+	nr->in[0] = 0x736e6f63;
+	nr->in[1] = 0x746e6174;
+	nr->in[2] = 0x72616720;
+	nr->in[3] = 0x65676162;
+	nr->in[4] = 0xc0ffee;
+	nr->in[5] = seed;
+	nr->in[6] = seed ^ 0xbeef;
+	nr->in[7] = 0xbabe;
+	nr->in[8] = 20120608;
+	nr->in[9] = 0;
+	nr->in[10] = 0;
+	nr->in[11] = 0;
+	nr->in[12] = 0;
+	nr->in[13] = 0;
+	nr->in[14] = 0;
+	nr->in[15] = 0;
 
 	Number_Of_Random_Generators++;
-
 	return (Number_Of_Random_Generators-1);
 }
 
diff --git a/source/backend/parser/parse.h b/source/backend/parser/parse.h
index ec5fdd3..b004290 100644
--- a/source/backend/parser/parse.h
+++ b/source/backend/parser/parse.h
@@ -216,6 +216,12 @@ enum
 };
 
 
+typedef struct {
+	uint32_t in[16];
+	uint32_t out[16];
+	int nrints;
+} next_rand_t;
+
 /*****************************************************************************
 * Global typedefs
 ******************************************************************************/
@@ -577,7 +583,8 @@ class Parser : public Task
 		// express.h/express.cpp
 		short Have_Vector;
 		unsigned int Number_Of_Random_Generators;
-		unsigned int *next_rand;
+		next_rand_t *next_rand;
+		void chacha(uint32_t *, uint32_t *);
 
 		bool Allow_Identifier_In_Call, Identifier_In_Call;
 
@@ -742,7 +749,7 @@ class Parser : public Task
 		void POV_strupr (char *s);
 		void POV_strlwr (char *s);
 
-		DBL stream_rand (int stream);
+		DBL stream_rand (next_rand_t*);
 		int stream_seed (int seed);
 
 		// fnsyntax.h/fnsyntax.cpp