diff --git a/.gitignore b/.gitignore
index 9e3363b..f222fb9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -33,6 +33,7 @@ custom/libcustcalc*
 endian
 endian_calc.h
 fposval.h
+have_arc4random.h
 have_ban_pragma.h
 have_const.h
 have_environ.h
diff --git a/Makefile b/Makefile
index 2a123de..06de238 100644
--- a/Makefile
+++ b/Makefile
@@ -534,6 +534,16 @@ have_uid_t.h:
 	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}
 	${V} echo '=-=-=-=-= private Makefile $@ rule end =-=-=-=-='
 
+have_environ.h:
+	${V} echo '=-=-=-=-= private Makefile $@ rule start =-=-=-=-='
+	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}
+	${V} echo '=-=-=-=-= private Makefile $@ rule end =-=-=-=-='
+
+have_arc4random.h:
+	${V} echo '=-=-=-=-= private Makefile $@ rule start =-=-=-=-='
+	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}
+	${V} echo '=-=-=-=-= private Makefile $@ rule end =-=-=-=-='
+
 have_newstr.h:
 	${V} echo '=-=-=-=-= private Makefile $@ rule start =-=-=-=-='
 	${Q} ${MAKE} ${XARG} -f ${MAKE_FILE} $@ ${XVAR}
diff --git a/Makefile.ship b/Makefile.ship
index 53c21fd..f1e88e9 100644
--- a/Makefile.ship
+++ b/Makefile.ship
@@ -379,19 +379,32 @@ HAVE_CONST=
 HAVE_UID_T=
 #HAVE_UID_T= -DHAVE_NO_UID_T
 
-# Determine if we have user environment external:
+# Determine if we have a non-NULL user environment external:
 #
-#	extern char **environ;
+#	extern char **environ;	/* user environment */
 #
 # If HAVE_ENVIRON is empty, this Makefile will run the have_environ program
-# to determine if environ exsuts.  If HAVE_ENVIRON is set to -DHAVE_NO_ENVIRON,
-# then calc will assume there is no external environ symbol.
+# to determine if environ exists and is non-NULL.  If HAVE_ENVIRON is set
+# to -DHAVE_NO_ENVIRON, then calc will assume there is no external environ
+# symbol.
 #
 # If in doubt, leave HAVE_ENVIRON empty and this Makefile will figure it out.
 #
 HAVE_ENVIRON=
 #HAVE_ENVIRON= -DHAVE_NO_ENVIRON
 
+# Determine if we have the arc4random_buf() function
+#
+# If HAVE_ARC4RANDOM is empty, this Makefile will run the have_arc4random
+# program to determine if arc4random_buf() function exists.  If
+# HAVE_ARC4RANDOM is set to -DHAVE_NO_ARC4RANDOM, then calc will assume
+# there is no arc4random_buf() function.
+#
+# If in doubt, leave HAVE_ARC4RANDOM empty and this Makefile will figure it out.
+#
+HAVE_ARC4RANDOM=
+#HAVE_ARC4RANDOM= -DHAVE_NO_ARC4RANDOM
+
 # Determine if we have memcpy(), memset() and strchr()
 #
 # If HAVE_NEWSTR is empty, this Makefile will run the have_newstr program
@@ -1927,7 +1940,7 @@ BUILD_H_SRC= align32.h args.h calcerr.h conf.h endian_calc.h \
 	have_posscl.h have_rusage.h have_stdlib.h have_strdup.h \
 	have_string.h have_strlcat.h have_strlcpy.h have_times.h \
 	have_uid_t.h have_unistd.h have_unused.h have_urandom.h \
-	have_ustat.h longbits.h terminal.h have_environ.h
+	have_ustat.h longbits.h terminal.h have_environ.h have_arc4random.h
 
 # we build these .c files during the make
 #
@@ -1942,7 +1955,8 @@ UTIL_C_SRC= align32.c endian.c longbits.c have_newstr.c have_uid_t.c \
 	have_fpos_pos.c have_offscl.c have_posscl.c have_memmv.c \
 	have_ustat.c have_getsid.c have_getpgid.c have_environ.c \
 	have_gettime.c have_getprid.c have_rusage.c have_strdup.c \
-	have_unused.c have_ban_pragma.c have_strlcpy.c have_strlcat.c
+	have_unused.c have_ban_pragma.c have_strlcpy.c have_strlcat.c \
+	have_arc4random.c
 
 # these awk and sed tools are used in the process of building BUILD_H_SRC
 # and BUILD_C_SRC
@@ -1959,7 +1973,8 @@ UTIL_OBJS= endian.o longbits.o have_newstr.o have_uid_t.o \
 	try_strarg.o have_stdvs.o have_varvs.o have_posscl.o have_memmv.o \
 	have_ustat.o have_getsid.o have_getpgid.o have_environ.o \
 	have_gettime.o have_getprid.o ver_calc.o have_rusage.o have_strdup.o \
-	have_unused.o have_ban_pragma.o have_strlcpy.o have_strlcat.o
+	have_unused.o have_ban_pragma.o have_strlcpy.o have_strlcat.o \
+	have_arc4random.o
 
 # these temp files may be created (and removed) during the build of BUILD_C_SRC
 #
@@ -1977,7 +1992,7 @@ UTIL_PROGS= align32${EXT} fposval${EXT} have_uid_t${EXT} have_const${EXT} \
 	ver_calc${EXT} have_strdup${EXT} have_environ{EXT} \
 	have_unused${EXT} have_fpos${EXT} have_fpos_pos${EXT} \
 	have_offscl${EXT} have_rusage${EXT} have_ban_pragma${EXT} \
-	have_strlcpy${EXT} have_strlcat${EXT}
+	have_strlcpy${EXT} have_strlcat${EXT} have_arc4random${EXT}
 
 # these utility files and scripts may be created in the process of building
 # the BUILD_H_SRC file set
@@ -3302,6 +3317,48 @@ have_environ.h: have_environ.c \
 	    ${TRUE}; \
 	fi
 
+have_arc4random.h: have_arc4random.c have_stdlib.h \
+	banned.h have_ban_pragma.h ${MAKE_FILE} ${LOC_MKF}
+	${Q} ${RM} -f have_arc4random arc4random_tmp $@
+	${H} echo 'forming $@'
+	${Q} echo '/*' > $@
+	${Q} echo ' * DO NOT EDIT -- generated by the Makefile' >> $@
+	${Q} echo ' */' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#if !defined(HAVE_ARC4RANDOM)' >> $@
+	${Q} echo '#define HAVE_ARC4RANDOM' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '/* do we have or want arc4random? */' >> $@
+	${Q} ${RM} -f have_arc4random.o have_arc4random${EXT}
+	-${Q} ${LCC} ${ICFLAGS} ${HAVE_arc4random} have_arc4random.c -c ${S} \
+		|| ${TRUE}
+	-${Q} ${LCC} ${ILDFLAGS} have_arc4random.o \
+		-o have_arc4random${EXT} ${S} \
+		|| ${TRUE}
+	-${Q} ./have_arc4random${EXT} > arc4random_tmp ${E} \
+		|| ${TRUE}
+	-${Q} if [ -s arc4random_tmp ]; then \
+	    ${CAT} arc4random_tmp >> $@; \
+	else \
+	    echo '#undef HAVE_arc4random /* no */' >> $@; \
+	fi
+	${Q} echo '' >> $@
+	${Q} echo '' >> $@
+	${Q} echo '#endif /* !HAVE_ARC4RANDOM */' >> $@
+	${Q} ${RM} -f have_arc4random${EXT} have_arc4random.o arc4random_tmp
+	${H} echo '$@ formed'
+	-@if [ -z "${Q}" ]; then \
+	    echo ''; \
+	    echo '=-=-= start of $@ =-=-='; \
+	    ${CAT} $@; \
+	    echo '=-=-= end of $@ =-=-='; \
+	    echo ''; \
+	else \
+	    ${TRUE}; \
+	fi
+
 have_newstr.h: have_newstr.c banned.h have_ban_pragma.h ${MAKE_FILE} ${LOC_MKF}
 	${Q} ${RM} -f newstr_tmp $@
 	${H} echo 'forming $@'
@@ -4478,6 +4535,7 @@ env:
 	@echo 'FPOS_POS_BITS=${FPOS_POS_BITS}'; echo ''
 	@echo 'GREP=${GREP}'; echo ''
 	@echo 'H=${H}'; echo ''
+	@echo 'HAVE_ARC4RANDOM=${HAVE_ARC4RANDOM}'; echo ''
 	@echo 'HAVE_CONST=${HAVE_CONST}'; echo ''
 	@echo 'HAVE_ENVIRON=${HAVE_ENVIRON}'; echo ''
 	@echo 'HAVE_FPOS=${HAVE_FPOS}'; echo ''
@@ -5866,6 +5924,10 @@ hash.o: value.h
 hash.o: zmath.h
 hash.o: zrand.h
 hash.o: zrandom.h
+have_arc4random.o: banned.h
+have_arc4random.o: have_arc4random.c
+have_arc4random.o: have_ban_pragma.h
+have_arc4random.o: have_stdlib.h
 have_ban_pragma.o: banned.h
 have_ban_pragma.o: have_ban_pragma.c
 have_ban_pragma.o: have_ban_pragma.h
@@ -6512,6 +6574,7 @@ seed.o: banned.h
 seed.o: byteswap.h
 seed.o: decl.h
 seed.o: endian_calc.h
+seed.o: have_arc4random.h
 seed.o: have_ban_pragma.h
 seed.o: have_const.h
 seed.o: have_environ.h
diff --git a/have_arc4random.c b/have_arc4random.c
new file mode 100644
index 0000000..082698f
--- /dev/null
+++ b/have_arc4random.c
@@ -0,0 +1,72 @@
+/*
+ * have_arc4random - Determine if we have the arc4random_buf() RNG
+ *
+ * Copyright (C) 2021  Landon Curt Noll
+ *
+ * Calc is open software; you can redistribute it and/or modify it under
+ * the terms of the version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * Calc is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU Lesser General
+ * Public License for more details.
+ *
+ * A copy of version 2.1 of the GNU Lesser General Public License is
+ * distributed with calc under the filename COPYING-LGPL.  You should have
+ * received a copy with calc; if not, write to Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Under source code control:	2021/12/06 23:58:51
+ * File existed as early as:	2021
+ *
+ * chongo <was here> /\oo/\	http://www.isthe.com/chongo/
+ * Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/
+ */
+
+/*
+ * usage:
+ *	have_arc4random
+ *
+ * Not all enviroments have the arc4random_buf() function,
+ * so this may not compile on your system.
+ *
+ * This prog outputs:
+ *
+ *	HAVE_ARC4RANDOM
+ *		defined ==> have arc4random_buf() call
+ *		undefined ==> do not have arc4random_buf() call
+ */
+
+#include "have_stdlib.h"
+#if defined(HAVE_STDLIB_H)
+#include <stdlib.h>
+#endif
+#include <stdio.h>
+
+
+#include "banned.h"	/* include after system header <> includes */
+
+
+#define BUFLEN (32)		/* length of the buffer to fill */
+
+
+int
+main(void)
+{
+#if defined(HAVE_NO_ARC4RANDOM)
+
+	printf("#undef HAVE_ARC4RANDOM /* no */\n");
+
+#else /* HAVE_NO_ARC4RANDOM */
+
+	static char buf[BUFLEN];	/* buffer for arc4random_buf() to fill */
+
+	arc4random_buf(buf, BUFLEN);
+	printf("#define HAVE_ARC4RANDOM /* yes */\n");
+
+#endif /* HAVE_NO_ARC4RANDOM */
+
+	/* exit(0); */
+	return 0;
+}
diff --git a/have_environ.c b/have_environ.c
index 3efbe31..56a16c2 100644
--- a/have_environ.c
+++ b/have_environ.c
@@ -1,5 +1,5 @@
 /*
- * have_environ - Determine if we have the environ user environment value
+ * have_environ - Determine if we have the environ user environment synbol
  *
  * Copyright (C) 2021  Landon Curt Noll
  *
@@ -37,8 +37,8 @@
  * This prog outputs:
  *
  *	HAVE_ENVIRON
- *		defined ==> environ is an extern symbol
- *		undefined ==> environ is NOT an extern symbol
+ *		defined ==> environ is an non-NULL extern symbol
+ *		undefined ==> environ is NOT an extern symbol or is NULL
  */
 
 #include <stdio.h>
@@ -47,9 +47,6 @@
 #include "banned.h"	/* include after system header <> includes */
 
 
-extern char **environ;	/* user environment */
-
-
 int
 main(void)
 {
@@ -57,13 +54,17 @@ main(void)
 
 	printf("#undef HAVE_ENVIRON /* no */\n");
 
-#else /* HAVE_NO_CONST */
+#else /* HAVE_NO_ENVIRON */
 
-	const char * const str = "const";
+	extern char **environ;
 
-	printf("#define HAVE_ENVIRON /* yes */\n");
+	if (environ == NULL) {
+		printf("#define HAVE_ENVIRON /* no */\n");
+	} else {
+		printf("#define HAVE_ENVIRON /* yes */\n");
+	}
 
-#endif /* HAVE_NO_CONST */
+#endif /* HAVE_NO_ENVIRON */
 
 	/* exit(0); */
 	return 0;
diff --git a/seed.c b/seed.c
index 542a2f9..88276fc 100644
--- a/seed.c
+++ b/seed.c
@@ -80,7 +80,7 @@
 #endif
 #if defined(HAVE_STDLIB_H)
 # include <stdlib.h>
-# define RANDOM_CNT (32)	/* double random() call repeat count */
+# define RANDOM_CNT (64)	/* double random() call repeat count */
 # define INITSTATE_SIZE (256)	/* initstate pool size */
 #endif
 #include <setjmp.h>
@@ -96,6 +96,7 @@
 #include "have_rusage.h"
 #include "have_uid_t.h"
 #include "have_environ.h"
+#include "have_arc4random.h"
 #if defined(HAVE_USTAT)
 # include <ustat.h>
 #endif
@@ -127,6 +128,11 @@ static hash64 prev_hash64 = { 0, 0 };	/* previous pseudo_seed() return or 0 */
 extern char **environ;	/* user environment */
 #endif /* HAVE_ENVIRON */
 
+#if defined(HAVE_ARC4RANDOM)
+#define ARC4_BUFLEN (256)
+static char arc4_buf[ARC4_BUFLEN];
+#endif /* HAVE_ARC4RANDOM */
+
 
 /*
  * call counter - number of times pseudo_seed() as been called
@@ -562,10 +568,11 @@ pseudo_seed(void)
     pash_hash = (unsigned)(prev_hash64.w32[0] ^ prev_hash64.w32[1]);
 #endif /* HAVE_B64 */
 
-    /* classic random seeded with time of day, count, prev hash */
+    /* classic 31-bit random seeded with time of day, count, prev hash */
     srandom((unsigned)(sdata.time) ^ (unsigned)call_count ^ past_hash);
-    for (j=0; j < RANDOM_CNT; ++j) {
+    for (j=0; j < RANDOM_CNT; j += 2) {
 	random_before[j] = random();
+	random_before[j+1] = (random() << 1);
     }
 
     /* initialize random state with the FNV hash of sdata */
@@ -579,9 +586,10 @@ pseudo_seed(void)
 			      INITSTATE_SIZE);
 #endif /* HAVE_B64 */
 
-    /* use random again with the new random state */
-    for (j=0; j < RANDOM_CNT; ++j) {
-	random_after[j] = random() ^ (random() << 1);
+    /* use 31-bit random some more with the new random state */
+    for (j=0; j < RANDOM_CNT; j += 2) {
+	random_after[j] = random();
+	random_after[j+1] = (random() << 1);
     }
 
     /*
@@ -604,6 +612,16 @@ pseudo_seed(void)
 				 sizeof(random_after));
 #endif /* HAVE_STDLIB_H */
 
+#if defined(HAVE_ARC4RANDOM)
+    /*
+     * hash from a cryptographic pseudo-random number generator
+     */
+    arc4random_buf(arc4_buf, ARC4_BUFLEN);
+    hash_val = private_hash64_buf(hash_val,
+				 (char *)arc4_buf,
+				 ARC4_BUFLEN);
+#endif /* HAVE_ARC4RANDOM */
+
     /*
      * load the hash data into the ZVALUE
      *
diff --git a/win32.mkdef b/win32.mkdef
index 1bcb634..4106ad7 100644
--- a/win32.mkdef
+++ b/win32.mkdef
@@ -33,6 +33,7 @@ HAVE_TIME_H=YES
 HAVE_SYS_TIME_H=NO
 HAVE_UNISTD_H=NO
 HAVE_ENVIRON=-DHAVE_NO_ENVIRON
+HAVE_ARC4RANDOM=-DHAVE_NO_ARC4RANDOM
 
 BINDIR=/usr/bin/calc
 LIBDIR=/lib/calc