diff --git a/hash/bsdsum.cpp b/hash/bsdsum.cpp
index ec3877b2..b367a168 100644
--- a/hash/bsdsum.cpp
+++ b/hash/bsdsum.cpp
@@ -16,17 +16,33 @@
 
 #include "bsdsum.hpp"
 
+#include "../debug.hpp"
 
+
+///////////////////////////////////////////////////////////////////////////////
 uint16_t
-bsdsum (const void *restrict _data, size_t size) {
-    const uint8_t *restrict data = static_cast<const uint8_t*> (_data);
+bsdsum (const uint8_t *const restrict first, const uint8_t *const restrict last)
+{
+    CHECK_LE (first, last);
+
     uint16_t accum = 0;
 
-    for (size_t i = 0; i < size; ++i) {
+    for (auto cursor = first; cursor != last; ++cursor) {
         accum  = (accum >> 1u) | ((accum & 0x01u) << 15u);
-        accum += data[i];
+        accum += *cursor;
     }
 
     return accum;
 }
 
+
+///////////////////////////////////////////////////////////////////////////////
+uint16_t
+bsdsum (const void *restrict data, size_t size)
+{
+    return bsdsum (
+        static_cast<const uint8_t*> (data),
+        static_cast<const uint8_t*> (data) + size
+    );
+}
+
diff --git a/hash/bsdsum.hpp b/hash/bsdsum.hpp
index 76f6c872..0add7602 100644
--- a/hash/bsdsum.hpp
+++ b/hash/bsdsum.hpp
@@ -20,6 +20,7 @@
 #include <cstdint>
 #include <cstdlib>
 
-uint16_t bsdsum (const void *restrict, size_t);
+uint16_t bsdsum (const void *restrict data, size_t bytes);
+uint16_t bsdsum (const uint8_t *restrict first, const uint8_t *restrict last);
 
 #endif
diff --git a/hash/crc.cpp b/hash/crc.cpp
index f29ce7ab..d0a7e5d6 100644
--- a/hash/crc.cpp
+++ b/hash/crc.cpp
@@ -19,6 +19,14 @@
 #include "../endian.hpp"
 #include "../debug.hpp"
 
+
+uint32_t
+crc32 (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    not_implemented ();
+}
+
+
 uint32_t
 crc32 (const void *restrict, size_t) {
     not_implemented ();
diff --git a/hash/crc.hpp b/hash/crc.hpp
index 50845409..4a511bf3 100644
--- a/hash/crc.hpp
+++ b/hash/crc.hpp
@@ -20,7 +20,8 @@
 #include <cstdint>
 #include <cstdlib>
 
-uint32_t crc32 (const void *restrict, size_t);
+uint32_t crc32 (const void *restrict data, size_t bytes);
+uint32_t crc32 (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
 #endif
 
diff --git a/hash/md2.cpp b/hash/md2.cpp
index 62890ab1..16155a1c 100644
--- a/hash/md2.cpp
+++ b/hash/md2.cpp
@@ -16,6 +16,7 @@
 
 #include "md2.hpp"
 
+#include "../debug.hpp"
 #include "../types.hpp"
 
 #include <array>
@@ -72,6 +73,16 @@ MD2::reset (void)
 
 ///////////////////////////////////////////////////////////////////////////////
 void
+MD2::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    CHECK_LE (first, last);
+
+    update (first, last - first);
+}
+
+
+//-----------------------------------------------------------------------------
+void
 MD2::update (const void *data, size_t size)
 {
     update (static_cast<const uint8_t*> (data), size);
diff --git a/hash/md2.hpp b/hash/md2.hpp
index 4b7c57d0..0e20e4b9 100644
--- a/hash/md2.hpp
+++ b/hash/md2.hpp
@@ -32,6 +32,7 @@ namespace util {
 
                 void update (const uint8_t *data, size_t len);
                 void update (const void    *data, size_t len);
+                void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
                 void finish (void);
                 digest_t digest (void) const;
diff --git a/hash/md4.cpp b/hash/md4.cpp
index 78616847..22e30333 100644
--- a/hash/md4.cpp
+++ b/hash/md4.cpp
@@ -17,8 +17,9 @@
 #include "md4.hpp"
 
 #include "../bitwise.hpp"
-#include "../types.hpp"
+#include "../debug.hpp"
 #include "../endian.hpp"
+#include "../types.hpp"
 
 #include <cstring>
 
@@ -71,6 +72,15 @@ MD4::reset (void) {
 }
 
 
+void
+MD4::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    CHECK_LE (first, last);
+
+    update (first, last - first);
+}
+
+
 void
 MD4::update (const void *data, size_t size)
     { update (static_cast<const uint8_t*> (data), size); }
diff --git a/hash/md4.hpp b/hash/md4.hpp
index aa4eab0f..4428404c 100644
--- a/hash/md4.hpp
+++ b/hash/md4.hpp
@@ -31,6 +31,7 @@ namespace util {
 
                 void update (const void    *data, size_t len);
                 void update (const uint8_t *data, size_t len);
+                void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
                 void finish (void);
                 digest_t digest (void) const;
diff --git a/hash/md5.cpp b/hash/md5.cpp
index c969fc4d..f9a2fa56 100644
--- a/hash/md5.cpp
+++ b/hash/md5.cpp
@@ -102,6 +102,15 @@ MD5::reset (void) {
 }
 
 
+void
+MD5::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    CHECK_LE (first, last);
+
+    update (first, last - first);
+}
+
+
 void
 MD5::update (const void *data, size_t len)
     { MD5::update (static_cast<const uint8_t*> (data), len); }
diff --git a/hash/md5.hpp b/hash/md5.hpp
index 4fbc23be..6d105bde 100644
--- a/hash/md5.hpp
+++ b/hash/md5.hpp
@@ -34,6 +34,7 @@ namespace util {
 
                 void update (const void    *data, size_t len);
                 void update (const uint8_t *data, size_t len);
+                void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
 
                 void finish (void);
                 digest_t digest (void) const;
diff --git a/hash/ripemd.cpp b/hash/ripemd.cpp
index 9680cda7..fbfe8098 100644
--- a/hash/ripemd.cpp
+++ b/hash/ripemd.cpp
@@ -49,6 +49,16 @@ RIPEMD::reset (void) {
 
 ///////////////////////////////////////////////////////////////////////////////
 void
+RIPEMD::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    CHECK_LE (first, last);
+
+    update (first, last - first);
+}
+
+
+//-----------------------------------------------------------------------------
+void
 RIPEMD::update (const uint8_t *data, size_t len) {
     CHECK (data);
 
diff --git a/hash/ripemd.hpp b/hash/ripemd.hpp
index c4237a01..17a56a30 100644
--- a/hash/ripemd.hpp
+++ b/hash/ripemd.hpp
@@ -30,6 +30,8 @@ namespace util {
                 RIPEMD();
 
                 void update (const uint8_t*, size_t);
+                void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
+
                 digest_t digest (void) const;
                 void finish (void);
                 void reset (void);
diff --git a/hash/sha1.cpp b/hash/sha1.cpp
index 7ebfc980..a0385399 100644
--- a/hash/sha1.cpp
+++ b/hash/sha1.cpp
@@ -104,6 +104,16 @@ SHA1::reset (void) {
 }
 
 
+//-----------------------------------------------------------------------------
+void
+SHA1::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    CHECK_LE (first, last);
+
+    update (first, last - first);
+}
+
+
 //-----------------------------------------------------------------------------
 void
 SHA1::update (const uint8_t *data, size_t size) {
diff --git a/hash/sha1.hpp b/hash/sha1.hpp
index 3cb837c1..8842cfd5 100644
--- a/hash/sha1.hpp
+++ b/hash/sha1.hpp
@@ -35,6 +35,8 @@ namespace util { namespace hash {
         SHA1();
 
         void update (const uint8_t *, size_t);
+        void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
+
         void finish (void);
         digest_t digest (void) const;
         void reset  (void);
diff --git a/hash/sha2.cpp b/hash/sha2.cpp
index 55057667..923ffad8 100644
--- a/hash/sha2.cpp
+++ b/hash/sha2.cpp
@@ -18,6 +18,7 @@
 #include "sha2.hpp"
 
 #include "../bitwise.hpp"
+#include "../debug.hpp"
 #include "../endian.hpp"
 
 #include <algorithm>
@@ -170,6 +171,15 @@ SHA256::SHA256 ():
 }
 
 
+void
+SHA256::update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept
+{
+    CHECK_LE (first, last);
+
+    update (first, last - first);
+}
+
+
 void
 SHA256::update (const uint8_t *data, size_t length) {
     while (length) {
diff --git a/hash/sha2.hpp b/hash/sha2.hpp
index 3827036f..91631922 100644
--- a/hash/sha2.hpp
+++ b/hash/sha2.hpp
@@ -31,6 +31,8 @@ namespace util {
                 SHA256();
 
                 void update (const uint8_t *, size_t);
+                void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
+
                 void finish (void);
                 digest_t digest (void) const;