diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90f1a1f..8fb5fc5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 2.1.0
+
+- Authorize encryption of already encrypted volumes (key migration)
+
+## 2.0.3
+
+- Adding a security check on KMS alias
+
 ## 2.0.2
 
 - Adding option for choosing to restart or not an instance after encryption
diff --git a/README.md b/README.md
index dd1b4e5..ff9bff5 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ Encrypt EBS volumes from AWS EC2 instances
 
 This tool let you :
 - Encrypt all the EBS volumes for an instance
+- If volumes already encrypted, re-encrypt these with the given key
 - Duplicate all the source tags to the target
 - Apply DeleteOnTermination flag if needs
 - Preserve the original volume or not as an option (thank to @cobaltjacket)
diff --git a/cmd/root.go b/cmd/root.go
index 845590c..3061904 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -51,9 +51,6 @@ func Execute() {
 func init() {
 	cobra.OnInitialize(initConfig)
 
-	// TODO: Not yet implemented
-	//rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.ec2cryptomatic.yaml)")
-
 }
 
 // initConfig reads in config file and ENV variables if set.
@@ -63,8 +60,7 @@ func initConfig() {
 		viper.SetConfigFile(cfgFile)
 	} else {
 		// Find home directory.
-		home, err := homedir.Dir()
-		if err != nil {
+		home, err := homedir.Dir();	if err != nil {
 			fmt.Println(err)
 			os.Exit(1)
 		}
diff --git a/cmd/run.go b/cmd/run.go
index efd2fa0..5f88852 100644
--- a/cmd/run.go
+++ b/cmd/run.go
@@ -48,24 +48,21 @@ var runCmd = &cobra.Command{
 
 		fmt.Print("\t\t-=[ EC2Cryptomatic ]=-\n")
 
-		awsSession, err := session.NewSession(&aws.Config{Region: aws.String(region)})
-		if err != nil {
+		awsSession, err := session.NewSession(&aws.Config{Region: aws.String(region)});	if err != nil {
 			log.Fatalln("Cannot create an AWS awsSession object: " + err.Error())
 		}
 
 		kmsService := kms.New(awsSession)
 		kmsInput := &kms.DescribeKeyInput{KeyId: aws.String(kmsAlias)}
-		_, errorKmsKey := kmsService.DescribeKey(kmsInput); if errorKmsKey != nil {
+		if _, errorKmsKey := kmsService.DescribeKey(kmsInput); errorKmsKey != nil {
 			log.Fatalln("Error with this key: " + errorKmsKey.Error())
 		}
 
-		ec2Instance, instanceError := ec2instance.New(awsSession, instanceID)
-		if instanceError != nil {
+		ec2Instance, instanceError := ec2instance.New(awsSession, instanceID); if instanceError != nil {
 			log.Fatalln(instanceError)
 		}
 
-		errorAlgorithm := algorithm.EncryptInstance(ec2Instance, kmsAlias, discard, startInstance)
-		if errorAlgorithm != nil {
+		if errorAlgorithm := algorithm.EncryptInstance(ec2Instance, kmsAlias, discard, startInstance); errorAlgorithm != nil {
 			log.Fatalln("/!\\ " + errorAlgorithm.Error())
 		}
 	},
diff --git a/constants/constants.go b/constants/constants.go
index 2c3d9ff..3071f2a 100644
--- a/constants/constants.go
+++ b/constants/constants.go
@@ -2,7 +2,7 @@ package constants
 
 const (
 	// VERSION is the overall version of the program
-	VERSION string = "2.0.2"
+	VERSION string = "2.1.0"
 	// VolumeMaxAttempts how many attempts EC2 EBS waiters will used between SDK actions (snapshot ebsvolume)
 	VolumeMaxAttempts int = 10000
 	// InstanceMaxAttempts how many attempts EC2 waiters will used between SDK actions (attach/detach ebsvolume)
diff --git a/internal/algorithm/encrypt_algorithm.go b/internal/algorithm/encrypt_algorithm.go
index 6a8c850..ba89c48 100644
--- a/internal/algorithm/encrypt_algorithm.go
+++ b/internal/algorithm/encrypt_algorithm.go
@@ -7,52 +7,43 @@ import (
 	"github.com/jbrt/ec2cryptomatic/internal/ec2instance"
 )
 
+var	nonEligibleForEncryptionError = errors.New("instance must be stopped and compatible with EBS encryption")
+
 // EncryptInstance will takes an instanceID and encrypt all the related EBS volumes
-func EncryptInstance(ec2 *ec2instance.Ec2Instance, kmsKeyAlias string, sourceDiscard bool, startInstance bool) error {
+func EncryptInstance(ec2 *ec2instance.Ec2Instance, kmsKeyAlias string, discardSource bool, startInstance bool) error {
 
 	if !ec2.IsStopped() || !ec2.IsSupportsEncryptedVolumes() {
-		return errors.New("instance must be stopped and compatible with EBS encryption")
+		return nonEligibleForEncryptionError
 	}
 
 	actionDone := false
 	for _, ebsVolume := range ec2.GetEBSMappedVolumes() {
 		log.Println("-- Beginning work on EBS volume " + *ebsVolume.Ebs.VolumeId)
 
-		sourceVolume, volumeError := ec2.GetEBSVolume(*ebsVolume.Ebs.VolumeId)
-		if volumeError != nil {
+		sourceVolume, volumeError := ec2.GetEBSVolume(*ebsVolume.Ebs.VolumeId); if volumeError != nil {
 			return errors.New("Problem with volume initialization: " + volumeError.Error())
 		}
 
-		if sourceVolume.IsEncrypted() {
-			log.Println("-- This volume is already encrypted nothing to do with this one")
-			continue
-		}
-
-		encryptedVolume, encryptedVolumeError := sourceVolume.EncryptVolume(kmsKeyAlias)
-		if encryptedVolumeError != nil {
+		encryptedVolume, encryptedVolumeError := sourceVolume.EncryptVolume(kmsKeyAlias); if encryptedVolumeError != nil {
 			log.Printf("Problem while encrypting volume: %s (%s)\n", *ebsVolume.Ebs.VolumeId, encryptedVolumeError.Error())
 			continue
 		}
 
-		swappingError := ec2.SwapBlockDevice(ebsVolume, encryptedVolume)
-		if swappingError != nil {
+		if swappingError := ec2.SwapBlockDevice(ebsVolume, encryptedVolume); swappingError != nil {
 			log.Println("Problem while trying to swap volumes: " + swappingError.Error())
 			continue
 		}
 
-		if sourceDiscard {
+		if discardSource {
 			_ = sourceVolume.DeleteVolume()
 		}
 		actionDone = true
 	}
 
-	if actionDone {
-		if startInstance {
-			log.Println("Let's starts instance " + *ec2.InstanceID)
-			startError := ec2.StartInstance()
-			if startError != nil {
-				return startError
-			}
+	if actionDone && startInstance {
+		log.Println("Let's starts instance " + *ec2.InstanceID)
+		if startError := ec2.StartInstance(); startError != nil {
+			return startError
 		}
 	}
 
diff --git a/internal/ebsvolume/ebsvolume.go b/internal/ebsvolume/ebsvolume.go
index 2bbbead..da423c1 100644
--- a/internal/ebsvolume/ebsvolume.go
+++ b/internal/ebsvolume/ebsvolume.go
@@ -43,8 +43,7 @@ func (v VolumeToEncrypt) takeSnapshot() (*ec2.Snapshot, error) {
 		VolumeId:    v.describe.VolumeId,
 	}
 
-	snapshot, errSnapshot := v.client.CreateSnapshot(snapShotInput)
-	if errSnapshot != nil {
+	snapshot, errSnapshot := v.client.CreateSnapshot(snapShotInput); if errSnapshot != nil {
 		return nil, errSnapshot
 	}
 
@@ -62,9 +61,8 @@ func (v VolumeToEncrypt) takeSnapshot() (*ec2.Snapshot, error) {
 
 // DeleteVolume will delete the given EBS volume
 func (v VolumeToEncrypt) DeleteVolume() error {
-	log.Println("--- Delete volume " + *v.volumeID)
-	_, errDelete := v.client.DeleteVolume(&ec2.DeleteVolumeInput{VolumeId: v.volumeID})
-	if errDelete != nil {
+	log.Println("---> Delete volume " + *v.volumeID)
+	if _, errDelete := v.client.DeleteVolume(&ec2.DeleteVolumeInput{VolumeId: v.volumeID}); errDelete != nil {
 		return errDelete
 	}
 	return nil
@@ -72,10 +70,9 @@ func (v VolumeToEncrypt) DeleteVolume() error {
 
 // EncryptVolume will produce an encrypted version of the EBS volume
 func (v VolumeToEncrypt) EncryptVolume(kmsKeyID string) (*ec2.Volume, error) {
-	log.Println("--- Start encryption process for volume " + *v.volumeID)
+	log.Println("---> Start encryption process for volume " + *v.volumeID)
 	encrypted := true
-	snapshot, errSnapshot := v.takeSnapshot()
-	if errSnapshot != nil {
+	snapshot, errSnapshot := v.takeSnapshot(); if errSnapshot != nil {
 		return nil, errSnapshot
 	}
 
@@ -88,19 +85,17 @@ func (v VolumeToEncrypt) EncryptVolume(kmsKeyID string) (*ec2.Volume, error) {
 	}
 
 	// Adding tags if needed
-	tagsWithoutAwsDedicatedTags := v.getTagSpecifications()
-	if tagsWithoutAwsDedicatedTags != nil {
+	if tagsWithoutAwsDedicatedTags := v.getTagSpecifications(); tagsWithoutAwsDedicatedTags != nil {
 		volumeInput.TagSpecifications = tagsWithoutAwsDedicatedTags
 	}
 
 	// If EBS volume is IO, let's get the IOPs parameter
 	if strings.HasPrefix(*v.describe.VolumeType, "io") {
-		log.Println("--- This volumes is IO one let's set IOPs to ", *v.describe.Iops)
+		log.Println("---> This volumes is IO one let's set IOPs to ", *v.describe.Iops)
 		volumeInput.Iops = aws.Int64(*v.describe.Iops)
 	}
 
-	volume, errVolume := v.client.CreateVolume(volumeInput)
-	if errVolume != nil {
+	volume, errVolume := v.client.CreateVolume(volumeInput); if errVolume != nil {
 		return nil, errVolume
 	}
 
@@ -127,12 +122,10 @@ func (v VolumeToEncrypt) IsEncrypted() bool {
 
 // New returns a well construct EC2Instance object ec2instance
 func New(ec2Client *ec2.EC2, volumeID string) (*VolumeToEncrypt, error) {
-
 	// Trying to describe the given ec2instance as security mechanism (ec2instance is exists ? credentials are ok ?)
-	input := &ec2.DescribeVolumesInput{VolumeIds: []*string{aws.String(volumeID)}}
-	describe, errDescribe := ec2Client.DescribeVolumes(input)
-	if errDescribe != nil {
-		log.Println("--- Cannot get information from volume " + volumeID)
+	volumeInput := &ec2.DescribeVolumesInput{VolumeIds: []*string{aws.String(volumeID)}}
+	describe, errDescribe := ec2Client.DescribeVolumes(volumeInput); if errDescribe != nil {
+		log.Println("---> Cannot get information from volume " + volumeID)
 		return nil, errDescribe
 	}
 
diff --git a/internal/ec2instance/ec2instance.go b/internal/ec2instance/ec2instance.go
index c2564b7..fb5d703 100644
--- a/internal/ec2instance/ec2instance.go
+++ b/internal/ec2instance/ec2instance.go
@@ -12,6 +12,8 @@ import (
 	"github.com/jbrt/ec2cryptomatic/internal/ebsvolume"
 )
 
+var unsupportedInstanceTypes = []string{"c1.", "m1.", "m2.", "t1."}
+
 // Ec2Instance is the main type of that package. Will be returned by new.
 // It contains all data relevant for an ec2instance
 type Ec2Instance struct {
@@ -27,8 +29,7 @@ func (e Ec2Instance) GetEBSMappedVolumes() []*ec2.InstanceBlockDeviceMapping {
 
 // GetEBSVolume returns a specific EBS volume with high level methods
 func (e Ec2Instance) GetEBSVolume(volumeID string) (*ebsvolume.VolumeToEncrypt, error) {
-	ebsVolume, volumeError := ebsvolume.New(e.ec2client, volumeID)
-	if volumeError != nil {
+	ebsVolume, volumeError := ebsvolume.New(e.ec2client, volumeID);	if volumeError != nil {
 		return nil, volumeError
 	}
 	return ebsVolume, nil
@@ -44,7 +45,6 @@ func (e Ec2Instance) IsStopped() bool {
 
 // IsSupportsEncryptedVolumes will check if the ec2instance supports EBS encrypted volumes (not all instances types support that).
 func (e Ec2Instance) IsSupportsEncryptedVolumes() bool {
-	unsupportedInstanceTypes := []string{"c1.", "m1.", "m2.", "t1."}
 	for _, instance := range unsupportedInstanceTypes {
 		if strings.HasPrefix(*e.describeInstance.InstanceType, instance) {
 			return false
@@ -57,8 +57,7 @@ func (e Ec2Instance) IsSupportsEncryptedVolumes() bool {
 func (e Ec2Instance) StartInstance() error {
 	log.Println("-- Start ec2instance " + *e.InstanceID)
 	input := &ec2.StartInstancesInput{InstanceIds: []*string{aws.String(*e.InstanceID)}}
-	_, errStart := e.ec2client.StartInstances(input)
-	if errStart != nil {
+	if _, errStart := e.ec2client.StartInstances(input); errStart != nil {
 		return errStart
 	}
 	return nil
@@ -67,8 +66,7 @@ func (e Ec2Instance) StartInstance() error {
 //SwapBlockDevice will swap two EBS volumes from an EC2 ec2instance
 func (e Ec2Instance) SwapBlockDevice(source *ec2.InstanceBlockDeviceMapping, target *ec2.Volume) error {
 	detach := &ec2.DetachVolumeInput{VolumeId: aws.String(*source.Ebs.VolumeId)}
-	_, errDetach := e.ec2client.DetachVolume(detach)
-	if errDetach != nil {
+	if _, errDetach := e.ec2client.DetachVolume(detach); errDetach != nil {
 		return errDetach
 	}
 
@@ -88,8 +86,7 @@ func (e Ec2Instance) SwapBlockDevice(source *ec2.InstanceBlockDeviceMapping, tar
 		VolumeId:   aws.String(*target.VolumeId),
 	}
 
-	_, errAttach := e.ec2client.AttachVolume(attach)
-	if errAttach != nil {
+	if _, errAttach := e.ec2client.AttachVolume(attach); errAttach != nil {
 		return errAttach
 	}
 
@@ -110,8 +107,7 @@ func (e Ec2Instance) SwapBlockDevice(source *ec2.InstanceBlockDeviceMapping, tar
 
 		requestModify, _ := e.ec2client.ModifyInstanceAttributeRequest(&attributeInput)
 
-		errorRequest := requestModify.Send()
-		if errorRequest != nil {
+		if errorRequest := requestModify.Send(); errorRequest != nil {
 			return errorRequest
 		}
 
@@ -122,16 +118,15 @@ func (e Ec2Instance) SwapBlockDevice(source *ec2.InstanceBlockDeviceMapping, tar
 
 // New returns a well construct EC2Instance object ec2instance
 func New(session *session.Session, instanceID string) (*Ec2Instance, error) {
-	log.Println("Let's encrypt ec2instance " + instanceID)
+	log.Println("Let's encrypt EC2 instance " + instanceID)
 
 	// Trying to describeInstance the given ec2instance as security mechanism (ec2instance is exists ? credentials are ok ?)
 	ec2client := ec2.New(session)
-	input := &ec2.DescribeInstancesInput{InstanceIds: []*string{aws.String(instanceID)}}
+	ec2Input := &ec2.DescribeInstancesInput{InstanceIds: []*string{aws.String(instanceID)}}
 
-	describe, errDescribe := ec2client.DescribeInstances(input)
-	if errDescribe != nil {
-		log.Println("-- Cannot find EC2 ec2instance " + instanceID)
-		return &Ec2Instance{}, errDescribe
+	describe, errDescribe := ec2client.DescribeInstances(ec2Input); if errDescribe != nil {
+		log.Println("-- Cannot find EC2 instance " + instanceID)
+		return nil, errDescribe
 	}
 
 	instance := &Ec2Instance{