diff --git a/stdlibs/crypto/sha1/sha1.gno b/stdlibs/crypto/sha1/sha1.gno
new file mode 100644
index 00000000000..80154703b9e
--- /dev/null
+++ b/stdlibs/crypto/sha1/sha1.gno
@@ -0,0 +1,19 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package sha1 implements the SHA-1 hash algorithm as defined in RFC 3174.
+//
+// SHA-1 is cryptographically broken and should not be used for secure
+// applications.
+
+package sha1
+
+import (
+	isha1 "internal/crypto/sha1" // XXX
+)
+
+// Sum returns the SHA-1 checksum of the data.
+func Sum(data []byte) []byte {
+	return isha1.Sum(data)
+}
\ No newline at end of file
diff --git a/stdlibs/crypto/sha1/sha1_test.gno b/stdlibs/crypto/sha1/sha1_test.gno
new file mode 100644
index 00000000000..1bfa4cdc042
--- /dev/null
+++ b/stdlibs/crypto/sha1/sha1_test.gno
@@ -0,0 +1,18 @@
+package sha1
+
+import (
+	"std"
+	"testing"
+
+	"crypto/sha1"
+	"encoding/hex"
+)
+
+func TestFunc(t *testing.T) {
+	got := sha1.Sum([]byte("sha1 this string"))
+	expected := "cf23df2207d99a74fbe169e3eba035e633b65d94"
+
+	if (hex.EncodeToString(got)) != expected {
+		t.Errorf("got %v(%T), expected %v(%T)", got, got, expected, expected)
+	}
+}
\ No newline at end of file
diff --git a/stdlibs/internal/crypto/sha1/sha1.gno b/stdlibs/internal/crypto/sha1/sha1.gno
new file mode 100644
index 00000000000..954d749bc69
--- /dev/null
+++ b/stdlibs/internal/crypto/sha1/sha1.gno
@@ -0,0 +1,3 @@
+package sha1
+
+// XXX injected via stdlibs/stdlibs.go
diff --git a/stdlibs/stdlibs.go b/stdlibs/stdlibs.go
index b365e43a14e..187f7372311 100644
--- a/stdlibs/stdlibs.go
+++ b/stdlibs/stdlibs.go
@@ -1,6 +1,7 @@
 package stdlibs
 
 import (
+	"crypto/sha1"
 	"math"
 	"reflect"
 	"strconv"
@@ -20,6 +21,31 @@ func InjectNativeMappings(store gno.Store) {
 
 func InjectPackage(store gno.Store, pn *gno.PackageNode) {
 	switch pn.PkgPath {
+	case "internal/crypto/sha1":
+		pn.DefineNative("Sum",
+			gno.Flds( // params
+				"data", "[]byte",
+			),
+			gno.Flds( // results
+				"bz", "[]byte",
+			),
+			func(m *gno.Machine) {
+				arg0 := m.LastBlock().GetParams1().TV
+				bz := []byte(nil)
+				if arg0.V != nil {
+					slice := arg0.V.(*gno.SliceValue)
+					array := slice.GetBase(m.Store)
+					bz = array.GetReadonlyBytes()
+				}
+				hash := sha1.Sum(bz)
+				res0 := gno.Go2GnoValue(
+					m.Alloc,
+					m.Store,
+					reflect.ValueOf([20]byte(hash)),
+				)
+				m.PushValue(res0)
+			},
+		)
 	case "internal/math":
 		pn.DefineNative("Float32bits",
 			gno.Flds( // params