diff --git a/merkletree/README.md b/merkletree/README.md
index 759554f..027e5c6 100644
--- a/merkletree/README.md
+++ b/merkletree/README.md
@@ -10,8 +10,7 @@ Initiate the history hash chain (the persistent authenticated dictionary)
 signKey := crypto.GenerateKey()
 
 // init STR history chain with maximum length is len
-// using DefaultPolicies as current policy
-pad := NewPAD(NewPolicies(epochDeadline), signKey, len)
+pad := NewPAD(NewPolicies(epochDeadline, vrfPrivKey), signKey, len)
 ```
 
 Update tree in each epoch
@@ -26,7 +25,7 @@ pad.Update(nil)
 
 Look-up
 
-`LookUp(key)` and `LookUpInEpoch(key, epoch)` return a `MerkleNode` instance and an `AuthenticationPath` for proofs of inclusion/absence.
+`LookUp(key)` and `LookUpInEpoch(key, epoch)` return an `AuthenticationPath` for proofs of inclusion/absence.
 A proof of absence also includes an empty leaf node in the returned auth path.
 
 ### TODO
diff --git a/merkletree/policy.go b/merkletree/policy.go
index 55fd44c..2f937d6 100644
--- a/merkletree/policy.go
+++ b/merkletree/policy.go
@@ -14,15 +14,15 @@ type Policies interface {
 	vrfPrivate() *[vrf.SecretKeySize]byte
 }
 
-type DefaultPolicies struct {
+type ConiksPolicies struct {
 	vrfPrivateKey *[vrf.SecretKeySize]byte
 	epochDeadline TimeStamp
 }
 
-var _ Policies = (*DefaultPolicies)(nil)
+var _ Policies = (*ConiksPolicies)(nil)
 
 func NewPolicies(epDeadline TimeStamp, vrfPrivKey *[vrf.SecretKeySize]byte) Policies {
-	return &DefaultPolicies{
+	return &ConiksPolicies{
 		epochDeadline: epDeadline,
 		vrfPrivateKey: vrfPrivKey,
 	}
@@ -30,7 +30,7 @@ func NewPolicies(epDeadline TimeStamp, vrfPrivKey *[vrf.SecretKeySize]byte) Poli
 
 // Serialize encodes the policy to a byte array with the following format:
 // [lib version, cryptographic algorithm in use, epoch deadline]
-func (p *DefaultPolicies) Serialize() []byte {
+func (p *ConiksPolicies) Serialize() []byte {
 	var bs []byte
 	bs = append(bs, []byte(Version)...)                            // lib Version
 	bs = append(bs, []byte(crypto.HashID)...)                      // cryptographic algorithms in use
@@ -39,10 +39,10 @@ func (p *DefaultPolicies) Serialize() []byte {
 	return bs
 }
 
-func (p *DefaultPolicies) vrfPrivate() *[vrf.SecretKeySize]byte {
+func (p *ConiksPolicies) vrfPrivate() *[vrf.SecretKeySize]byte {
 	return p.vrfPrivateKey
 }
 
-func (p *DefaultPolicies) EpochDeadline() TimeStamp {
+func (p *ConiksPolicies) EpochDeadline() TimeStamp {
 	return p.epochDeadline
 }