diff --git a/src/restic/archiver/archiver_duplication_test.go b/src/restic/archiver/archiver_duplication_test.go
index 37bed0830..9f0867d5e 100644
--- a/src/restic/archiver/archiver_duplication_test.go
+++ b/src/restic/archiver/archiver_duplication_test.go
@@ -11,9 +11,8 @@ import (
 	"github.com/pkg/errors"
 
 	"restic"
-	"restic/backend"
+	"restic/archiver"
 	"restic/mock"
-	"restic/pack"
 	"restic/repository"
 )
 
@@ -21,14 +20,14 @@ const parallelSaves = 50
 const testSaveIndexTime = 100 * time.Millisecond
 const testTimeout = 2 * time.Second
 
-var DupID backend.ID
+var DupID restic.ID
 
-func randomID() backend.ID {
+func randomID() restic.ID {
 	if mrand.Float32() < 0.5 {
 		return DupID
 	}
 
-	id := backend.ID{}
+	id := restic.ID{}
 	_, err := io.ReadFull(rand.Reader, id[:])
 	if err != nil {
 		panic(err)
@@ -52,8 +51,8 @@ func forgetfulBackend() restic.Backend {
 		return nil
 	}
 
-	be.StatFn = func(h restic.Handle) (restic.BlobInfo, error) {
-		return restic.BlobInfo{}, errors.New("not found")
+	be.StatFn = func(h restic.Handle) (restic.FileInfo, error) {
+		return restic.FileInfo{}, errors.New("not found")
 	}
 
 	be.RemoveFn = func(t restic.FileType, name string) error {
@@ -86,7 +85,7 @@ func testArchiverDuplication(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	arch := restic.NewArchiver(repo)
+	arch := archiver.New(repo)
 
 	wg := &sync.WaitGroup{}
 	done := make(chan struct{})
diff --git a/src/restic/archiver/archiver_int_test.go b/src/restic/archiver/archiver_int_test.go
index 28305b38f..3b5309a20 100644
--- a/src/restic/archiver/archiver_int_test.go
+++ b/src/restic/archiver/archiver_int_test.go
@@ -2,6 +2,7 @@ package archiver
 
 import (
 	"os"
+	"restic"
 	"testing"
 
 	"restic/pipe"
diff --git a/src/restic/archiver/archiver_test.go b/src/restic/archiver/archiver_test.go
index 57903931a..176a01802 100644
--- a/src/restic/archiver/archiver_test.go
+++ b/src/restic/archiver/archiver_test.go
@@ -7,10 +7,9 @@ import (
 	"time"
 
 	"restic"
-	"restic/backend"
+	"restic/archiver"
 	"restic/checker"
 	"restic/crypto"
-	"restic/pack"
 	. "restic/test"
 
 	"github.com/pkg/errors"
@@ -101,7 +100,7 @@ func archiveDirectory(b testing.TB) {
 	repo := SetupRepo()
 	defer TeardownRepo(repo)
 
-	arch := restic.NewArchiver(repo)
+	arch := archiver.New(repo)
 
 	_, id, err := arch.Snapshot(nil, []string{BenchArchiveDirectory}, nil)
 	OK(b, err)
@@ -191,48 +190,6 @@ func TestArchiveDedup(t *testing.T) {
 	archiveWithDedup(t)
 }
 
-func BenchmarkLoadTree(t *testing.B) {
-	repo := SetupRepo()
-	defer TeardownRepo(repo)
-
-	if BenchArchiveDirectory == "" {
-		t.Skip("benchdir not set, skipping TestArchiverDedup")
-	}
-
-	// archive a few files
-	arch := restic.NewArchiver(repo)
-	sn, _, err := arch.Snapshot(nil, []string{BenchArchiveDirectory}, nil)
-	OK(t, err)
-	t.Logf("archived snapshot %v", sn.ID())
-
-	list := make([]backend.ID, 0, 10)
-	done := make(chan struct{})
-
-	for _, idx := range repo.Index().All() {
-		for blob := range idx.Each(done) {
-			if blob.Type != restic.TreeBlob {
-				continue
-			}
-
-			list = append(list, blob.ID)
-			if len(list) == cap(list) {
-				close(done)
-				break
-			}
-		}
-	}
-
-	// start benchmark
-	t.ResetTimer()
-
-	for i := 0; i < t.N; i++ {
-		for _, id := range list {
-			_, err := restic.LoadTree(repo, id)
-			OK(t, err)
-		}
-	}
-}
-
 // Saves several identical chunks concurrently and later checks that there are no
 // unreferenced packs in the repository. See also #292 and #358.
 func TestParallelSaveWithDuplication(t *testing.T) {
@@ -248,7 +205,7 @@ func testParallelSaveWithDuplication(t *testing.T, seed int) {
 	dataSizeMb := 128
 	duplication := 7
 
-	arch := restic.NewArchiver(repo)
+	arch := archiver.New(repo)
 	chunks := getRandomData(seed, dataSizeMb*1024*1024)
 
 	errChannels := [](<-chan error){}
@@ -265,7 +222,7 @@ func testParallelSaveWithDuplication(t *testing.T, seed int) {
 			go func(c chunker.Chunk, errChan chan<- error) {
 				barrier <- struct{}{}
 
-				id := backend.Hash(c.Data)
+				id := restic.Hash(c.Data)
 				time.Sleep(time.Duration(id[0]))
 				err := arch.Save(restic.DataBlob, c.Data, id)
 				<-barrier
@@ -301,7 +258,7 @@ func getRandomData(seed int, size int) []chunker.Chunk {
 	return chunks
 }
 
-func createAndInitChecker(t *testing.T, repo Repository) *checker.Checker {
+func createAndInitChecker(t *testing.T, repo restic.Repository) *checker.Checker {
 	chkr := checker.New(repo)
 
 	hints, errs := chkr.LoadIndex()
diff --git a/src/restic/checker/checker.go b/src/restic/checker/checker.go
index 6bcea9b81..3b488cced 100644
--- a/src/restic/checker/checker.go
+++ b/src/restic/checker/checker.go
@@ -32,11 +32,11 @@ type Checker struct {
 
 	masterIndex *repository.MasterIndex
 
-	repo *repository.Repository
+	repo restic.Repository
 }
 
 // New returns a new checker which runs on repo.
-func New(repo *repository.Repository) *Checker {
+func New(repo restic.Repository) *Checker {
 	c := &Checker{
 		packs:       restic.NewIDSet(),
 		blobs:       restic.NewIDSet(),
@@ -180,7 +180,7 @@ func (e PackError) Error() string {
 	return "pack " + e.ID.String() + ": " + e.Err.Error()
 }
 
-func packIDTester(repo *repository.Repository, inChan <-chan restic.ID, errChan chan<- error, wg *sync.WaitGroup, done <-chan struct{}) {
+func packIDTester(repo restic.Repository, inChan <-chan restic.ID, errChan chan<- error, wg *sync.WaitGroup, done <-chan struct{}) {
 	debug.Log("Checker.testPackID", "worker start")
 	defer debug.Log("Checker.testPackID", "worker done")
 
@@ -273,7 +273,7 @@ func (e Error) Error() string {
 	return e.Err.Error()
 }
 
-func loadTreeFromSnapshot(repo *repository.Repository, id restic.ID) (restic.ID, error) {
+func loadTreeFromSnapshot(repo restic.Repository, id restic.ID) (restic.ID, error) {
 	sn, err := restic.LoadSnapshot(repo, id)
 	if err != nil {
 		debug.Log("Checker.loadTreeFromSnapshot", "error loading snapshot %v: %v", id.Str(), err)
@@ -289,7 +289,7 @@ func loadTreeFromSnapshot(repo *repository.Repository, id restic.ID) (restic.ID,
 }
 
 // loadSnapshotTreeIDs loads all snapshots from backend and returns the tree IDs.
-func loadSnapshotTreeIDs(repo *repository.Repository) (restic.IDs, []error) {
+func loadSnapshotTreeIDs(repo restic.Repository) (restic.IDs, []error) {
 	var trees struct {
 		IDs restic.IDs
 		sync.Mutex
@@ -349,7 +349,7 @@ type treeJob struct {
 }
 
 // loadTreeWorker loads trees from repo and sends them to out.
-func loadTreeWorker(repo *repository.Repository,
+func loadTreeWorker(repo restic.Repository,
 	in <-chan restic.ID, out chan<- treeJob,
 	done <-chan struct{}, wg *sync.WaitGroup) {
 
@@ -660,7 +660,7 @@ func (c *Checker) CountPacks() uint64 {
 }
 
 // checkPack reads a pack and checks the integrity of all blobs.
-func checkPack(r *repository.Repository, id restic.ID) error {
+func checkPack(r restic.Repository, id restic.ID) error {
 	debug.Log("Checker.checkPack", "checking pack %v", id.Str())
 	h := restic.Handle{FileType: restic.DataFile, Name: id.String()}
 	buf, err := backend.LoadAll(r.Backend(), h, nil)
diff --git a/src/restic/checker/checker_test.go b/src/restic/checker/checker_test.go
index e719cd229..6e9f29d06 100644
--- a/src/restic/checker/checker_test.go
+++ b/src/restic/checker/checker_test.go
@@ -8,7 +8,7 @@ import (
 	"testing"
 
 	"restic"
-	"restic/backend"
+	"restic/archiver"
 	"restic/backend/mem"
 	"restic/checker"
 	"restic/repository"
@@ -147,7 +147,7 @@ func TestUnreferencedBlobs(t *testing.T) {
 		snID := "51d249d28815200d59e4be7b3f21a157b864dc343353df9d8e498220c2499b02"
 		OK(t, repo.Backend().Remove(restic.SnapshotFile, snID))
 
-		unusedBlobsBySnapshot := backend.IDs{
+		unusedBlobsBySnapshot := restic.IDs{
 			ParseID("58c748bbe2929fdf30c73262bd8313fe828f8925b05d1d4a87fe109082acb849"),
 			ParseID("988a272ab9768182abfd1fe7d7a7b68967825f0b861d3b36156795832c772235"),
 			ParseID("c01952de4d91da1b1b80bc6e06eaa4ec21523f4853b69dc8231708b9b7ec62d8"),
@@ -212,7 +212,7 @@ func TestDuplicatePacksInIndex(t *testing.T) {
 
 // errorBackend randomly modifies data after reading.
 type errorBackend struct {
-	backend.Backend
+	restic.Backend
 	ProduceErrors bool
 }
 
@@ -244,7 +244,7 @@ func TestCheckerModifiedData(t *testing.T) {
 	repo := repository.New(be)
 	OK(t, repo.Init(TestPassword))
 
-	arch := restic.NewArchiver(repo)
+	arch := archiver.New(repo)
 	_, id, err := arch.Snapshot(nil, []string{"."}, nil)
 	OK(t, err)
 	t.Logf("archived as %v", id.Str())
diff --git a/src/restic/index/index.go b/src/restic/index/index.go
index 7d8f47250..e2f7f8317 100644
--- a/src/restic/index/index.go
+++ b/src/restic/index/index.go
@@ -5,10 +5,8 @@ import (
 	"fmt"
 	"os"
 	"restic"
-	"restic/backend"
 	"restic/debug"
 	"restic/list"
-	"restic/pack"
 	"restic/worker"
 
 	"github.com/pkg/errors"
@@ -17,27 +15,27 @@ import (
 // Pack contains information about the contents of a pack.
 type Pack struct {
 	Size    int64
-	Entries []pack.Blob
+	Entries []restic.Blob
 }
 
 // Blob contains information about a blob.
 type Blob struct {
 	Size  int64
-	Packs backend.IDSet
+	Packs restic.IDSet
 }
 
 // Index contains information about blobs and packs stored in a repo.
 type Index struct {
-	Packs    map[backend.ID]Pack
-	Blobs    map[pack.Handle]Blob
-	IndexIDs backend.IDSet
+	Packs    map[restic.ID]Pack
+	Blobs    map[restic.BlobHandle]Blob
+	IndexIDs restic.IDSet
 }
 
 func newIndex() *Index {
 	return &Index{
-		Packs:    make(map[backend.ID]Pack),
-		Blobs:    make(map[pack.Handle]Blob),
-		IndexIDs: backend.NewIDSet(),
+		Packs:    make(map[restic.ID]Pack),
+		Blobs:    make(map[restic.BlobHandle]Blob),
+		IndexIDs: restic.NewIDSet(),
 	}
 }
 
@@ -57,7 +55,7 @@ func New(repo restic.Repository, p *restic.Progress) (*Index, error) {
 	for job := range ch {
 		p.Report(restic.Stat{Blobs: 1})
 
-		packID := job.Data.(backend.ID)
+		packID := job.Data.(restic.ID)
 		if job.Error != nil {
 			fmt.Fprintf(os.Stderr, "unable to list pack %v: %v\n", packID.Str(), job.Error)
 			continue
@@ -82,23 +80,23 @@ func New(repo restic.Repository, p *restic.Progress) (*Index, error) {
 const loadIndexParallelism = 20
 
 type packJSON struct {
-	ID    backend.ID `json:"id"`
+	ID    restic.ID  `json:"id"`
 	Blobs []blobJSON `json:"blobs"`
 }
 
 type blobJSON struct {
-	ID     backend.ID    `json:"id"`
-	Type   pack.BlobType `json:"type"`
-	Offset uint          `json:"offset"`
-	Length uint          `json:"length"`
+	ID     restic.ID       `json:"id"`
+	Type   restic.BlobType `json:"type"`
+	Offset uint            `json:"offset"`
+	Length uint            `json:"length"`
 }
 
 type indexJSON struct {
-	Supersedes backend.IDs `json:"supersedes,omitempty"`
+	Supersedes restic.IDs  `json:"supersedes,omitempty"`
 	Packs      []*packJSON `json:"packs"`
 }
 
-func loadIndexJSON(repo restic.Repository, id backend.ID) (*indexJSON, error) {
+func loadIndexJSON(repo restic.Repository, id restic.ID) (*indexJSON, error) {
 	debug.Log("index.loadIndexJSON", "process index %v\n", id.Str())
 
 	var idx indexJSON
@@ -120,8 +118,8 @@ func Load(repo restic.Repository, p *restic.Progress) (*Index, error) {
 	done := make(chan struct{})
 	defer close(done)
 
-	supersedes := make(map[backend.ID]backend.IDSet)
-	results := make(map[backend.ID]map[backend.ID]Pack)
+	supersedes := make(map[restic.ID]restic.IDSet)
+	results := make(map[restic.ID]map[restic.ID]Pack)
 
 	index := newIndex()
 
@@ -134,17 +132,17 @@ func Load(repo restic.Repository, p *restic.Progress) (*Index, error) {
 			return nil, err
 		}
 
-		res := make(map[backend.ID]Pack)
-		supersedes[id] = backend.NewIDSet()
+		res := make(map[restic.ID]Pack)
+		supersedes[id] = restic.NewIDSet()
 		for _, sid := range idx.Supersedes {
 			debug.Log("index.Load", "  index %v supersedes %v", id.Str(), sid)
 			supersedes[id].Insert(sid)
 		}
 
 		for _, jpack := range idx.Packs {
-			entries := make([]pack.Blob, 0, len(jpack.Blobs))
+			entries := make([]restic.Blob, 0, len(jpack.Blobs))
 			for _, blob := range jpack.Blobs {
-				entry := pack.Blob{
+				entry := restic.Blob{
 					ID:     blob.ID,
 					Type:   blob.Type,
 					Offset: blob.Offset,
@@ -178,7 +176,7 @@ func Load(repo restic.Repository, p *restic.Progress) (*Index, error) {
 
 // AddPack adds a pack to the index. If this pack is already in the index, an
 // error is returned.
-func (idx *Index) AddPack(id backend.ID, size int64, entries []pack.Blob) error {
+func (idx *Index) AddPack(id restic.ID, size int64, entries []restic.Blob) error {
 	if _, ok := idx.Packs[id]; ok {
 		return errors.Errorf("pack %v already present in the index", id.Str())
 	}
@@ -186,11 +184,11 @@ func (idx *Index) AddPack(id backend.ID, size int64, entries []pack.Blob) error
 	idx.Packs[id] = Pack{Size: size, Entries: entries}
 
 	for _, entry := range entries {
-		h := pack.Handle{ID: entry.ID, Type: entry.Type}
+		h := restic.BlobHandle{ID: entry.ID, Type: entry.Type}
 		if _, ok := idx.Blobs[h]; !ok {
 			idx.Blobs[h] = Blob{
 				Size:  int64(entry.Length),
-				Packs: backend.NewIDSet(),
+				Packs: restic.NewIDSet(),
 			}
 		}
 
@@ -201,13 +199,13 @@ func (idx *Index) AddPack(id backend.ID, size int64, entries []pack.Blob) error
 }
 
 // RemovePack deletes a pack from the index.
-func (idx *Index) RemovePack(id backend.ID) error {
+func (idx *Index) RemovePack(id restic.ID) error {
 	if _, ok := idx.Packs[id]; !ok {
 		return errors.Errorf("pack %v not found in the index", id.Str())
 	}
 
 	for _, blob := range idx.Packs[id].Entries {
-		h := pack.Handle{ID: blob.ID, Type: blob.Type}
+		h := restic.BlobHandle{ID: blob.ID, Type: blob.Type}
 		idx.Blobs[h].Packs.Delete(id)
 
 		if len(idx.Blobs[h].Packs) == 0 {
@@ -222,13 +220,13 @@ func (idx *Index) RemovePack(id backend.ID) error {
 
 // DuplicateBlobs returns a list of blobs that are stored more than once in the
 // repo.
-func (idx *Index) DuplicateBlobs() (dups pack.BlobSet) {
-	dups = pack.NewBlobSet()
-	seen := pack.NewBlobSet()
+func (idx *Index) DuplicateBlobs() (dups restic.BlobSet) {
+	dups = restic.NewBlobSet()
+	seen := restic.NewBlobSet()
 
 	for _, p := range idx.Packs {
 		for _, entry := range p.Entries {
-			h := pack.Handle{ID: entry.ID, Type: entry.Type}
+			h := restic.BlobHandle{ID: entry.ID, Type: entry.Type}
 			if seen.Has(h) {
 				dups.Insert(h)
 			}
@@ -240,8 +238,8 @@ func (idx *Index) DuplicateBlobs() (dups pack.BlobSet) {
 }
 
 // PacksForBlobs returns the set of packs in which the blobs are contained.
-func (idx *Index) PacksForBlobs(blobs pack.BlobSet) (packs backend.IDSet) {
-	packs = backend.NewIDSet()
+func (idx *Index) PacksForBlobs(blobs restic.BlobSet) (packs restic.IDSet) {
+	packs = restic.NewIDSet()
 
 	for h := range blobs {
 		blob, ok := idx.Blobs[h]
@@ -259,8 +257,8 @@ func (idx *Index) PacksForBlobs(blobs pack.BlobSet) (packs backend.IDSet) {
 
 // Location describes the location of a blob in a pack.
 type Location struct {
-	PackID backend.ID
-	pack.Blob
+	PackID restic.ID
+	restic.Blob
 }
 
 // ErrBlobNotFound is return by FindBlob when the blob could not be found in
@@ -268,7 +266,7 @@ type Location struct {
 var ErrBlobNotFound = errors.New("blob not found in index")
 
 // FindBlob returns a list of packs and positions the blob can be found in.
-func (idx *Index) FindBlob(h pack.Handle) ([]Location, error) {
+func (idx *Index) FindBlob(h restic.BlobHandle) ([]Location, error) {
 	blob, ok := idx.Blobs[h]
 	if !ok {
 		return nil, ErrBlobNotFound
@@ -299,8 +297,8 @@ func (idx *Index) FindBlob(h pack.Handle) ([]Location, error) {
 }
 
 // Save writes the complete index to the repo.
-func (idx *Index) Save(repo restic.Repository, supersedes backend.IDs) (backend.ID, error) {
-	packs := make(map[backend.ID][]pack.Blob, len(idx.Packs))
+func (idx *Index) Save(repo restic.Repository, supersedes restic.IDs) (restic.ID, error) {
+	packs := make(map[restic.ID][]restic.Blob, len(idx.Packs))
 	for id, p := range idx.Packs {
 		packs[id] = p.Entries
 	}
@@ -309,7 +307,7 @@ func (idx *Index) Save(repo restic.Repository, supersedes backend.IDs) (backend.
 }
 
 // Save writes a new index containing the given packs.
-func Save(repo restic.Repository, packs map[backend.ID][]pack.Blob, supersedes backend.IDs) (backend.ID, error) {
+func Save(repo restic.Repository, packs map[restic.ID][]restic.Blob, supersedes restic.IDs) (restic.ID, error) {
 	idx := &indexJSON{
 		Supersedes: supersedes,
 		Packs:      make([]*packJSON, 0, len(packs)),
diff --git a/src/restic/index/index_test.go b/src/restic/index/index_test.go
index 0f273a1c5..521d0c0b0 100644
--- a/src/restic/index/index_test.go
+++ b/src/restic/index/index_test.go
@@ -3,8 +3,6 @@ package index
 import (
 	"math/rand"
 	"restic"
-	"restic/backend"
-	"restic/pack"
 	"restic/repository"
 	. "restic/test"
 	"testing"
@@ -179,7 +177,7 @@ func TestIndexSave(t *testing.T) {
 
 	idx := loadIndex(t, repo)
 
-	packs := make(map[backend.ID][]pack.Blob)
+	packs := make(map[restic.ID][]restic.Blob)
 	for id := range idx.Packs {
 		if rand.Float32() < 0.5 {
 			packs[id] = idx.Packs[id].Entries
@@ -248,7 +246,7 @@ func TestIndexAddRemovePack(t *testing.T) {
 	}
 
 	for _, blob := range blobs {
-		h := pack.Handle{ID: blob.ID, Type: blob.Type}
+		h := restic.BlobHandle{ID: blob.ID, Type: blob.Type}
 		_, err := idx.FindBlob(h)
 		if err == nil {
 			t.Errorf("removed blob %v found in index", h)
@@ -308,7 +306,7 @@ func TestIndexLoadDocReference(t *testing.T) {
 	idx := loadIndex(t, repo)
 
 	blobID := ParseID("d3dc577b4ffd38cc4b32122cabf8655a0223ed22edfd93b353dc0c3f2b0fdf66")
-	locs, err := idx.FindBlob(pack.Handle{ID: blobID, Type: pack.Data})
+	locs, err := idx.FindBlob(restic.BlobHandle{ID: blobID, Type: restic.DataBlob})
 	if err != nil {
 		t.Errorf("FindBlob() returned error %v", err)
 	}
@@ -322,8 +320,8 @@ func TestIndexLoadDocReference(t *testing.T) {
 		t.Errorf("blob IDs are not equal: %v != %v", l.ID, blobID)
 	}
 
-	if l.Type != pack.Data {
-		t.Errorf("want type %v, got %v", pack.Data, l.Type)
+	if l.Type != restic.DataBlob {
+		t.Errorf("want type %v, got %v", restic.DataBlob, l.Type)
 	}
 
 	if l.Offset != 150 {
diff --git a/src/restic/pack/pack_test.go b/src/restic/pack/pack_test.go
index bfafa0631..5e5b1fc1e 100644
--- a/src/restic/pack/pack_test.go
+++ b/src/restic/pack/pack_test.go
@@ -10,7 +10,6 @@ import (
 	"restic"
 	"testing"
 
-	"restic/backend"
 	"restic/backend/mem"
 	"restic/crypto"
 	"restic/pack"
@@ -21,7 +20,7 @@ var testLens = []int{23, 31650, 25860, 10928, 13769, 19862, 5211, 127, 13690, 30
 
 type Buf struct {
 	data []byte
-	id   backend.ID
+	id   restic.ID
 }
 
 func newPack(t testing.TB, k *crypto.Key, lengths []int) ([]Buf, []byte, uint) {
@@ -38,7 +37,7 @@ func newPack(t testing.TB, k *crypto.Key, lengths []int) ([]Buf, []byte, uint) {
 	// pack blobs
 	p := pack.NewPacker(k, nil)
 	for _, b := range bufs {
-		p.Add(pack.Tree, b.id, b.data)
+		p.Add(restic.TreeBlob, b.id, b.data)
 	}
 
 	_, err := p.Finalize()
@@ -56,7 +55,7 @@ func verifyBlobs(t testing.TB, bufs []Buf, k *crypto.Key, rd io.ReaderAt, packSi
 	// header length
 	written += binary.Size(uint32(0))
 	// header
-	written += len(bufs) * (binary.Size(pack.BlobType(0)) + binary.Size(uint32(0)) + backend.IDSize)
+	written += len(bufs) * (binary.Size(restic.BlobType(0)) + binary.Size(uint32(0)) + restic.IDSize)
 	// header crypto
 	written += crypto.Extension
 
@@ -96,11 +95,11 @@ func TestCreatePack(t *testing.T) {
 }
 
 var blobTypeJSON = []struct {
-	t   pack.BlobType
+	t   restic.BlobType
 	res string
 }{
-	{pack.Data, `"data"`},
-	{pack.Tree, `"tree"`},
+	{restic.DataBlob, `"data"`},
+	{restic.TreeBlob, `"tree"`},
 }
 
 func TestBlobTypeJSON(t *testing.T) {
@@ -111,7 +110,7 @@ func TestBlobTypeJSON(t *testing.T) {
 		Equals(t, test.res, string(buf))
 
 		// test unserialize
-		var v pack.BlobType
+		var v restic.BlobType
 		err = json.Unmarshal([]byte(test.res), &v)
 		OK(t, err)
 		Equals(t, test.t, v)
@@ -125,9 +124,9 @@ func TestUnpackReadSeeker(t *testing.T) {
 	bufs, packData, packSize := newPack(t, k, testLens)
 
 	b := mem.New()
-	id := backend.Hash(packData)
+	id := restic.Hash(packData)
 
-	handle := restic.Handle{Type: restic.DataFile, Name: id.String()}
+	handle := restic.Handle{FileType: restic.DataFile, Name: id.String()}
 	OK(t, b.Save(handle, packData))
 	verifyBlobs(t, bufs, k, restic.ReaderAt(b, handle), packSize)
 }
@@ -138,9 +137,9 @@ func TestShortPack(t *testing.T) {
 	bufs, packData, packSize := newPack(t, k, []int{23})
 
 	b := mem.New()
-	id := backend.Hash(packData)
+	id := restic.Hash(packData)
 
-	handle := restic.Handle{Type: restic.DataFile, Name: id.String()}
+	handle := restic.Handle{FileType: restic.DataFile, Name: id.String()}
 	OK(t, b.Save(handle, packData))
-	verifyBlobs(t, bufs, k, backend.ReaderAt(b, handle), packSize)
+	verifyBlobs(t, bufs, k, restic.ReaderAt(b, handle), packSize)
 }
diff --git a/src/restic/repository.go b/src/restic/repository.go
index 9bd22dabb..060a8f3a9 100644
--- a/src/restic/repository.go
+++ b/src/restic/repository.go
@@ -1,5 +1,7 @@
 package restic
 
+import "restic/crypto"
+
 // Repository stores data in a backend. It provides high-level functions and
 // transparently encrypts/decrypts data.
 type Repository interface {
@@ -7,6 +9,8 @@ type Repository interface {
 	// Backend returns the backend used by the repository
 	Backend() Backend
 
+	Key() *crypto.Key
+
 	SetIndex(Index)
 
 	Index() Index
@@ -24,6 +28,7 @@ type Repository interface {
 	LoadJSONPack(BlobType, ID, interface{}) error
 	LoadJSONUnpacked(FileType, ID, interface{}) error
 	LoadBlob(ID, BlobType, []byte) ([]byte, error)
+	LoadAndDecrypt(FileType, ID) ([]byte, error)
 
 	LookupBlobSize(ID, BlobType) (uint, error)
 
@@ -47,4 +52,5 @@ type Lister interface {
 type Index interface {
 	Has(ID, BlobType) bool
 	Lookup(ID, BlobType) ([]PackedBlob, error)
+	Count(BlobType) uint
 }
diff --git a/src/restic/repository/index.go b/src/restic/repository/index.go
index 266b5d79a..f543a25ec 100644
--- a/src/restic/repository/index.go
+++ b/src/restic/repository/index.go
@@ -534,7 +534,7 @@ func DecodeOldIndex(rd io.Reader) (idx *Index, err error) {
 }
 
 // LoadIndexWithDecoder loads the index and decodes it with fn.
-func LoadIndexWithDecoder(repo *Repository, id restic.ID, fn func(io.Reader) (*Index, error)) (idx *Index, err error) {
+func LoadIndexWithDecoder(repo restic.Repository, id restic.ID, fn func(io.Reader) (*Index, error)) (idx *Index, err error) {
 	debug.Log("LoadIndexWithDecoder", "Loading index %v", id[:8])
 
 	buf, err := repo.LoadAndDecrypt(restic.IndexFile, id)
diff --git a/src/restic/repository/index_test.go b/src/restic/repository/index_test.go
index 6b45d5990..65e8cdbd7 100644
--- a/src/restic/repository/index_test.go
+++ b/src/restic/repository/index_test.go
@@ -5,8 +5,6 @@ import (
 	"restic"
 	"testing"
 
-	"restic/backend"
-	"restic/pack"
 	"restic/repository"
 	. "restic/test"
 )
@@ -24,24 +22,26 @@ func TestIndexSerialize(t *testing.T) {
 
 	// create 50 packs with 20 blobs each
 	for i := 0; i < 50; i++ {
-		packID := backend.RandomID()
+		packID := restic.TestRandomID()
 
 		pos := uint(0)
 		for j := 0; j < 20; j++ {
-			id := backend.RandomID()
+			id := restic.TestRandomID()
 			length := uint(i*100 + j)
-			idx.Store(repository.PackedBlob{
-				Type:   pack.Data,
-				ID:     id,
+			idx.Store(restic.PackedBlob{
+				Blob: restic.Blob{
+					Type:   restic.DataBlob,
+					ID:     id,
+					Offset: pos,
+					Length: length,
+				},
 				PackID: packID,
-				Offset: pos,
-				Length: length,
 			})
 
 			tests = append(tests, testEntry{
 				id:     id,
 				pack:   packID,
-				tpe:    pack.Data,
+				tpe:    restic.DataBlob,
 				offset: pos,
 				length: length,
 			})
@@ -94,24 +94,26 @@ func TestIndexSerialize(t *testing.T) {
 	// add more blobs to idx
 	newtests := []testEntry{}
 	for i := 0; i < 10; i++ {
-		packID := backend.RandomID()
+		packID := restic.TestRandomID()
 
 		pos := uint(0)
 		for j := 0; j < 10; j++ {
-			id := backend.RandomID()
+			id := restic.TestRandomID()
 			length := uint(i*100 + j)
-			idx.Store(repository.PackedBlob{
-				Type:   pack.Data,
-				ID:     id,
+			idx.Store(restic.PackedBlob{
+				Blob: restic.Blob{
+					Type:   restic.DataBlob,
+					ID:     id,
+					Offset: pos,
+					Length: length,
+				},
 				PackID: packID,
-				Offset: pos,
-				Length: length,
 			})
 
 			newtests = append(newtests, testEntry{
 				id:     id,
 				pack:   packID,
-				tpe:    pack.Data,
+				tpe:    restic.DataBlob,
 				offset: pos,
 				length: length,
 			})
@@ -128,7 +130,7 @@ func TestIndexSerialize(t *testing.T) {
 	Assert(t, idx.Final(),
 		"index not final after encoding")
 
-	id := backend.RandomID()
+	id := restic.TestRandomID()
 	OK(t, idx.SetID(id))
 	id2, err := idx.ID()
 	Assert(t, id2.Equal(id),
@@ -165,18 +167,20 @@ func TestIndexSize(t *testing.T) {
 	packs := 200
 	blobs := 100
 	for i := 0; i < packs; i++ {
-		packID := backend.RandomID()
+		packID := restic.TestRandomID()
 
 		pos := uint(0)
 		for j := 0; j < blobs; j++ {
-			id := backend.RandomID()
+			id := restic.TestRandomID()
 			length := uint(i*100 + j)
-			idx.Store(repository.PackedBlob{
-				Type:   pack.Data,
-				ID:     id,
+			idx.Store(restic.PackedBlob{
+				Blob: restic.Blob{
+					Type:   restic.DataBlob,
+					ID:     id,
+					Offset: pos,
+					Length: length,
+				},
 				PackID: packID,
-				Offset: pos,
-				Length: length,
 			})
 
 			pos += length
@@ -257,15 +261,15 @@ var exampleTests = []struct {
 	{
 		ParseID("3ec79977ef0cf5de7b08cd12b874cd0f62bbaf7f07f3497a5b1bbcc8cb39b1ce"),
 		ParseID("73d04e6125cf3c28a299cc2f3cca3b78ceac396e4fcf9575e34536b26782413c"),
-		pack.Data, 0, 25,
+		restic.DataBlob, 0, 25,
 	}, {
 		ParseID("9ccb846e60d90d4eb915848add7aa7ea1e4bbabfc60e573db9f7bfb2789afbae"),
 		ParseID("73d04e6125cf3c28a299cc2f3cca3b78ceac396e4fcf9575e34536b26782413c"),
-		pack.Tree, 38, 100,
+		restic.TreeBlob, 38, 100,
 	}, {
 		ParseID("d3dc577b4ffd38cc4b32122cabf8655a0223ed22edfd93b353dc0c3f2b0fdf66"),
 		ParseID("73d04e6125cf3c28a299cc2f3cca3b78ceac396e4fcf9575e34536b26782413c"),
-		pack.Data, 150, 123,
+		restic.DataBlob, 150, 123,
 	},
 }
 
@@ -275,9 +279,9 @@ var exampleLookupTest = struct {
 }{
 	ParseID("73d04e6125cf3c28a299cc2f3cca3b78ceac396e4fcf9575e34536b26782413c"),
 	map[restic.ID]restic.BlobType{
-		ParseID("3ec79977ef0cf5de7b08cd12b874cd0f62bbaf7f07f3497a5b1bbcc8cb39b1ce"): pack.Data,
-		ParseID("9ccb846e60d90d4eb915848add7aa7ea1e4bbabfc60e573db9f7bfb2789afbae"): pack.Tree,
-		ParseID("d3dc577b4ffd38cc4b32122cabf8655a0223ed22edfd93b353dc0c3f2b0fdf66"): pack.Data,
+		ParseID("3ec79977ef0cf5de7b08cd12b874cd0f62bbaf7f07f3497a5b1bbcc8cb39b1ce"): restic.DataBlob,
+		ParseID("9ccb846e60d90d4eb915848add7aa7ea1e4bbabfc60e573db9f7bfb2789afbae"): restic.TreeBlob,
+		ParseID("d3dc577b4ffd38cc4b32122cabf8655a0223ed22edfd93b353dc0c3f2b0fdf66"): restic.DataBlob,
 	},
 }
 
@@ -349,13 +353,15 @@ func TestIndexPacks(t *testing.T) {
 	packs := restic.NewIDSet()
 
 	for i := 0; i < 20; i++ {
-		packID := backend.RandomID()
-		idx.Store(repository.PackedBlob{
-			Type:   pack.Data,
-			ID:     backend.RandomID(),
+		packID := restic.TestRandomID()
+		idx.Store(restic.PackedBlob{
+			Blob: restic.Blob{
+				Type:   restic.DataBlob,
+				ID:     restic.TestRandomID(),
+				Offset: 0,
+				Length: 23,
+			},
 			PackID: packID,
-			Offset: 0,
-			Length: 23,
 		})
 
 		packs.Insert(packID)
diff --git a/src/restic/repository/packer_manager_test.go b/src/restic/repository/packer_manager_test.go
index 0e99e2e90..323051612 100644
--- a/src/restic/repository/packer_manager_test.go
+++ b/src/restic/repository/packer_manager_test.go
@@ -7,7 +7,6 @@ import (
 	"restic"
 	"restic/backend/mem"
 	"restic/crypto"
-	"restic/pack"
 	"testing"
 )
 
@@ -64,7 +63,7 @@ func saveFile(t testing.TB, be Saver, filename string, n int) {
 		t.Fatal(err)
 	}
 
-	h := restic.Handle{Type: restic.DataFile, Name: restic.Hash(data).String()}
+	h := restic.Handle{FileType: restic.DataFile, Name: restic.Hash(data).String()}
 
 	err = be.Save(h, data)
 	if err != nil {
@@ -95,7 +94,7 @@ func fillPacks(t testing.TB, rnd *randReader, be Saver, pm *packerManager, buf [
 			t.Fatal(err)
 		}
 
-		n, err := packer.Add(pack.Data, id, buf)
+		n, err := packer.Add(restic.DataBlob, id, buf)
 		if n != l {
 			t.Errorf("Add() returned invalid number of bytes: want %v, got %v", n, l)
 		}
diff --git a/src/restic/repository/repack_test.go b/src/restic/repository/repack_test.go
index 804cf77f1..026e43cbc 100644
--- a/src/restic/repository/repack_test.go
+++ b/src/restic/repository/repack_test.go
@@ -4,7 +4,6 @@ import (
 	"io"
 	"math/rand"
 	"restic"
-	"restic/pack"
 	"restic/repository"
 	"testing"
 )
@@ -32,18 +31,18 @@ func createRandomBlobs(t testing.TB, repo *repository.Repository, blobs int, pDa
 		)
 
 		if rand.Float32() < pData {
-			tpe = pack.Data
+			tpe = restic.DataBlob
 			length = randomSize(10*1024, 1024*1024) // 10KiB to 1MiB of data
 		} else {
-			tpe = pack.Tree
+			tpe = restic.TreeBlob
 			length = randomSize(1*1024, 20*1024) // 1KiB to 20KiB
 		}
 
 		buf := random(t, length)
 		id := restic.Hash(buf)
 
-		if repo.Index().Has(id, pack.Data) {
-			t.Errorf("duplicate blob %v/%v ignored", id, pack.Data)
+		if repo.Index().Has(id, restic.DataBlob) {
+			t.Errorf("duplicate blob %v/%v ignored", id, restic.DataBlob)
 			continue
 		}
 
@@ -66,14 +65,14 @@ func createRandomBlobs(t testing.TB, repo *repository.Repository, blobs int, pDa
 
 // selectBlobs splits the list of all blobs randomly into two lists. A blob
 // will be contained in the firstone ith probability p.
-func selectBlobs(t *testing.T, repo *repository.Repository, p float32) (list1, list2 pack.BlobSet) {
+func selectBlobs(t *testing.T, repo *repository.Repository, p float32) (list1, list2 restic.BlobSet) {
 	done := make(chan struct{})
 	defer close(done)
 
-	list1 = pack.NewBlobSet()
-	list2 = pack.NewBlobSet()
+	list1 = restic.NewBlobSet()
+	list2 = restic.NewBlobSet()
 
-	blobs := pack.NewBlobSet()
+	blobs := restic.NewBlobSet()
 
 	for id := range repo.List(restic.DataFile, done) {
 		entries, _, err := repo.ListPack(id)
@@ -82,7 +81,7 @@ func selectBlobs(t *testing.T, repo *repository.Repository, p float32) (list1, l
 		}
 
 		for _, entry := range entries {
-			h := pack.Handle{ID: entry.ID, Type: entry.Type}
+			h := restic.BlobHandle{ID: entry.ID, Type: entry.Type}
 			if blobs.Has(h) {
 				t.Errorf("ignoring duplicate blob %v", h)
 				continue
@@ -90,9 +89,9 @@ func selectBlobs(t *testing.T, repo *repository.Repository, p float32) (list1, l
 			blobs.Insert(h)
 
 			if rand.Float32() <= p {
-				list1.Insert(pack.Handle{ID: entry.ID, Type: entry.Type})
+				list1.Insert(restic.BlobHandle{ID: entry.ID, Type: entry.Type})
 			} else {
-				list2.Insert(pack.Handle{ID: entry.ID, Type: entry.Type})
+				list2.Insert(restic.BlobHandle{ID: entry.ID, Type: entry.Type})
 			}
 
 		}
@@ -113,7 +112,7 @@ func listPacks(t *testing.T, repo *repository.Repository) restic.IDSet {
 	return list
 }
 
-func findPacksForBlobs(t *testing.T, repo *repository.Repository, blobs pack.BlobSet) restic.IDSet {
+func findPacksForBlobs(t *testing.T, repo *repository.Repository, blobs restic.BlobSet) restic.IDSet {
 	packs := restic.NewIDSet()
 
 	idx := repo.Index()
@@ -131,7 +130,7 @@ func findPacksForBlobs(t *testing.T, repo *repository.Repository, blobs pack.Blo
 	return packs
 }
 
-func repack(t *testing.T, repo *repository.Repository, packs restic.IDSet, blobs pack.BlobSet) {
+func repack(t *testing.T, repo *repository.Repository, packs restic.IDSet, blobs restic.BlobSet) {
 	err := repository.Repack(repo, packs, blobs)
 	if err != nil {
 		t.Fatal(err)
diff --git a/src/restic/repository/repository_test.go b/src/restic/repository/repository_test.go
index 4e27b8943..98b8edd84 100644
--- a/src/restic/repository/repository_test.go
+++ b/src/restic/repository/repository_test.go
@@ -11,7 +11,6 @@ import (
 	"testing"
 
 	"restic"
-	"restic/pack"
 	"restic/repository"
 	. "restic/test"
 )
@@ -36,7 +35,7 @@ func TestSaveJSON(t *testing.T) {
 		data = append(data, '\n')
 		h := sha256.Sum256(data)
 
-		id, err := repo.SaveJSON(pack.Tree, obj)
+		id, err := repo.SaveJSON(restic.TreeBlob, obj)
 		OK(t, err)
 
 		Assert(t, h == id,
@@ -59,7 +58,7 @@ func BenchmarkSaveJSON(t *testing.B) {
 	t.ResetTimer()
 
 	for i := 0; i < t.N; i++ {
-		id, err := repo.SaveJSON(pack.Tree, obj)
+		id, err := repo.SaveJSON(restic.TreeBlob, obj)
 		OK(t, err)
 
 		Assert(t, h == id,
@@ -82,7 +81,7 @@ func TestSave(t *testing.T) {
 		id := restic.Hash(data)
 
 		// save
-		sid, err := repo.SaveAndEncrypt(pack.Data, data, nil)
+		sid, err := repo.SaveAndEncrypt(restic.DataBlob, data, nil)
 		OK(t, err)
 
 		Equals(t, id, sid)
@@ -91,7 +90,7 @@ func TestSave(t *testing.T) {
 		// OK(t, repo.SaveIndex())
 
 		// read back
-		buf, err := repo.LoadBlob(id, pack.Data, make([]byte, size))
+		buf, err := repo.LoadBlob(id, restic.DataBlob, make([]byte, size))
 		OK(t, err)
 
 		Assert(t, len(buf) == len(data),
@@ -116,14 +115,14 @@ func TestSaveFrom(t *testing.T) {
 		id := restic.Hash(data)
 
 		// save
-		id2, err := repo.SaveAndEncrypt(pack.Data, data, &id)
+		id2, err := repo.SaveAndEncrypt(restic.DataBlob, data, &id)
 		OK(t, err)
 		Equals(t, id, id2)
 
 		OK(t, repo.Flush())
 
 		// read back
-		buf, err := repo.LoadBlob(id, pack.Data, make([]byte, size))
+		buf, err := repo.LoadBlob(id, restic.DataBlob, make([]byte, size))
 		OK(t, err)
 
 		Assert(t, len(buf) == len(data),
@@ -153,7 +152,7 @@ func BenchmarkSaveAndEncrypt(t *testing.B) {
 
 	for i := 0; i < t.N; i++ {
 		// save
-		_, err = repo.SaveAndEncrypt(pack.Data, data, &id)
+		_, err = repo.SaveAndEncrypt(restic.DataBlob, data, &id)
 		OK(t, err)
 	}
 }
@@ -171,7 +170,7 @@ func TestLoadJSONPack(t *testing.T) {
 	OK(t, repo.Flush())
 
 	tree := restic.NewTree()
-	err := repo.LoadJSONPack(pack.Tree, *sn.Tree, &tree)
+	err := repo.LoadJSONPack(restic.TreeBlob, *sn.Tree, &tree)
 	OK(t, err)
 }
 
@@ -192,7 +191,7 @@ func BenchmarkLoadJSONPack(t *testing.B) {
 	t.ResetTimer()
 
 	for i := 0; i < t.N; i++ {
-		err := repo.LoadJSONPack(pack.Tree, *sn.Tree, &tree)
+		err := repo.LoadJSONPack(restic.TreeBlob, *sn.Tree, &tree)
 		OK(t, err)
 	}
 }
@@ -253,7 +252,7 @@ func saveRandomDataBlobs(t testing.TB, repo *repository.Repository, num int, siz
 		_, err := io.ReadFull(rand.Reader, buf)
 		OK(t, err)
 
-		_, err = repo.SaveAndEncrypt(pack.Data, buf, nil)
+		_, err = repo.SaveAndEncrypt(restic.DataBlob, buf, nil)
 		OK(t, err)
 	}
 }