metainfo/file-tree.go          |  9 +++++++++
 metainfo/info.go               |  8 ++++++--
 metainfo/metainfo.go           | 10 ++++++----
 peer_protocol/handshake.go     | 11 +++++++----
 peer_protocol/reserved_test.go | 13 +++++++++++++
 types/infohash/infohash.go     |  8 ++++++++

diff --git a/metainfo/file-tree.go b/metainfo/file-tree.go
new file mode 100644
index 0000000000000000000000000000000000000000..0bccb15365cd8e9f6bc92a709304d92a4613eba8
--- /dev/null
+++ b/metainfo/file-tree.go
@@ -0,0 +1,9 @@
+package metainfo
+
+type FileTree struct {
+	File struct {
+		Length     int64  `bencode:"length"`
+		PiecesRoot string `bencode:"pieces root"`
+	}
+	Dir map[string]FileTree
+}
diff --git a/metainfo/info.go b/metainfo/info.go
index 1ee2704ec97b760025eda2a951966a8174665626..5eedfa3b4c41730ddb92543abfb855ad635e27e4 100644
--- a/metainfo/info.go
+++ b/metainfo/info.go
@@ -11,7 +11,7 @@
 	"github.com/anacrolix/missinggo/v2/slices"
 )
 
-// The info dictionary.
+// The info dictionary. See BEP 3 and BEP 52.
 type Info struct {
 	PieceLength int64  `bencode:"piece length"` // BEP3
 	Pieces      []byte `bencode:"pieces"`       // BEP3
@@ -22,6 +22,10 @@ 	Private     *bool  `bencode:"private,omitempty"` // BEP27
 	// TODO: Document this field.
 	Source string     `bencode:"source,omitempty"`
 	Files  []FileInfo `bencode:"files,omitempty"` // BEP3, mutually exclusive with Length
+
+	// BEP 52 (BitTorrent v2)
+	MetaVersion int64    `bencode:"meta version,omitempty"`
+	FileTree    FileTree `bencode:"file tree,omitempty"`
 }
 
 // The Info.Name field is "advisory". For multi-file torrents it's usually a suggested directory
@@ -157,7 +161,7 @@ func (info *Info) Piece(index int) Piece {
 	return Piece{info, pieceIndex(index)}
 }
 
-func (info Info) BestName() string {
+func (info *Info) BestName() string {
 	if info.NameUtf8 != "" {
 		return info.NameUtf8
 	}
diff --git a/metainfo/metainfo.go b/metainfo/metainfo.go
index 93f9103b968b09f661cb3aa9a9a6618a8102cdb6..9f4109899c7a6b54f202a0c14f43cfbcd8806722 100644
--- a/metainfo/metainfo.go
+++ b/metainfo/metainfo.go
@@ -10,6 +10,7 @@
 	"github.com/anacrolix/torrent/bencode"
 )
 
+// Also known as a torrent file.
 type MetaInfo struct {
 	InfoBytes    bencode.Bytes `bencode:"info,omitempty"`                              // BEP 3
 	Announce     string        `bencode:"announce,omitempty"`                          // BEP 3
@@ -23,10 +24,12 @@ 	Comment      string  `bencode:"comment,omitempty"`
 	CreatedBy    string  `bencode:"created by,omitempty"`
 	Encoding     string  `bencode:"encoding,omitempty"`
 	UrlList      UrlList `bencode:"url-list,omitempty"` // BEP 19 WebSeeds
+	// BEP 52 (BitTorrent v2): Keys are file merkle roots (pieces root?), and the values are the
+	// concatenated hashes of the merkle tree layer that corresponds to the piece length.
+	PieceLayers map[string]string `bencode:"piece layers,omitempty"`
 }
 
-// Load a MetaInfo from an io.Reader. Returns a non-nil error in case of
-// failure.
+// Load a MetaInfo from an io.Reader. Returns a non-nil error in case of failure.
 func Load(r io.Reader) (*MetaInfo, error) {
 	var mi MetaInfo
 	d := bencode.NewDecoder(r)
@@ -85,8 +88,7 @@ 	m.Params["ws"] = mi.UrlList
 	return
 }
 
-// Returns the announce list converted from the old single announce field if
-// necessary.
+// Returns the announce-list converted from the old single announce field if necessary.
 func (mi *MetaInfo) UpvertedAnnounceList() AnnounceList {
 	if mi.AnnounceList.OverridesAnnounce(mi.Announce) {
 		return mi.AnnounceList
diff --git a/peer_protocol/handshake.go b/peer_protocol/handshake.go
index a6f648cfe6e16ea3a6b147dd8bd5490a14c57022..bce28340bbe8c60d75c4aa735ae1c42d790a9990 100644
--- a/peer_protocol/handshake.go
+++ b/peer_protocol/handshake.go
@@ -18,9 +18,12 @@
 // https://www.bittorrent.org/beps/bep_0004.html
 // https://wiki.theory.org/BitTorrentSpecification.html#Reserved_Bytes
 const (
-	ExtensionBitDht                          = 0 // http://www.bittorrent.org/beps/bep_0005.html
-	ExtensionBitFast                         = 2 // http://www.bittorrent.org/beps/bep_0006.html
-	ExtensionBitV2                           = 7 // "Hybrid torrent legacy to v2 upgrade"
+	ExtensionBitDht  = 0 // http://www.bittorrent.org/beps/bep_0005.html
+	ExtensionBitFast = 2 // http://www.bittorrent.org/beps/bep_0006.html
+	// A peer connection initiator can set this when sending a v1 infohash during handshake if they
+	// allow the receiving end to upgrade to v2 by responding with the corresponding v2 infohash.
+	// BEP 52, and BEP 4
+	ExtensionBitV2Upgrade                    = 4
 	ExtensionBitAzureusExtensionNegotiation1 = 16
 	ExtensionBitAzureusExtensionNegotiation2 = 17
 	// LibTorrent Extension Protocol, http://www.bittorrent.org/beps/bep_0010.html
@@ -56,7 +59,7 @@ 	{ExtensionBitLocationAwareProtocol, "loc"},
 	{ExtensionBitLtep, "ltep"},
 	{ExtensionBitAzureusExtensionNegotiation2, "azen2"},
 	{ExtensionBitAzureusExtensionNegotiation1, "azen1"},
-	{ExtensionBitV2, "v2"},
+	{ExtensionBitV2Upgrade, "v2"},
 	{ExtensionBitFast, "fast"},
 	{ExtensionBitDht, "dht"},
 }
diff --git a/peer_protocol/reserved_test.go b/peer_protocol/reserved_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..8ee3a722779c15cd1ace08eb6fe5fd140c770c62
--- /dev/null
+++ b/peer_protocol/reserved_test.go
@@ -0,0 +1,13 @@
+package peer_protocol
+
+import (
+	qt "github.com/frankban/quicktest"
+	"testing"
+)
+
+func TestV2BitLocation(t *testing.T) {
+	var bits PeerExtensionBits
+	bits.SetBit(ExtensionBitV2Upgrade, true)
+	c := qt.New(t)
+	c.Assert(bits[7], qt.Equals, byte(0x10))
+}
diff --git a/testdata/bittorrent-v2-hybrid-test.torrent b/testdata/bittorrent-v2-hybrid-test.torrent
new file mode 100644
index 0000000000000000000000000000000000000000..9a5c8762d6cfd0c2ebf61bace1498871aab7a648
Binary files /dev/null and b/testdata/bittorrent-v2-hybrid-test.torrent differ
diff --git a/testdata/bittorrent-v2-test.torrent b/testdata/bittorrent-v2-test.torrent
new file mode 100644
index 0000000000000000000000000000000000000000..8ad4c7eab07617e0c2b5c53df29c58d629cf3566
Binary files /dev/null and b/testdata/bittorrent-v2-test.torrent differ
diff --git a/types/infohash/infohash.go b/types/infohash/infohash.go
index 0763b01e0e8c4243e186407a22019b5620ba3f67..c90f7451e45d443d4889904a450c3552bf166cbf 100644
--- a/types/infohash/infohash.go
+++ b/types/infohash/infohash.go
@@ -2,6 +2,7 @@ package infohash
 
 import (
 	"crypto/sha1"
+	"crypto/sha256"
 	"encoding"
 	"encoding/hex"
 	"fmt"
@@ -78,3 +79,10 @@ 	hasher.Write(b)
 	copy(ret[:], hasher.Sum(nil))
 	return
 }
+
+func HashBytesV2(b []byte) (ret T) {
+	hasher := sha256.New()
+	hasher.Write(b)
+	copy(ret[:], hasher.Sum(nil))
+	return
+}