diff --git a/vault/core.go b/vault/core.go
index 15d5d07f12..646077e288 100644
--- a/vault/core.go
+++ b/vault/core.go
@@ -1,11 +1,37 @@
 package vault
 
 import (
+	"encoding/json"
+	"errors"
 	"fmt"
+	"log"
+	"sync"
 
 	"github.com/hashicorp/vault/physical"
 )
 
+const (
+	// coreSealConfigPath is the path used to store our seal configuration.
+	// This value is stored in plaintext, since we must be able to read
+	// it even with the Vault sealed. This is required so that we know
+	// how many secret parts must be used to reconstruct the master key.
+	coreSealConfigPath = "core/seal-config"
+)
+
+var (
+	// ErrSealed is returned if an operation is performed on
+	// a sealed barrier. No operation is expected to succeed before unsealing
+	ErrSealed = errors.New("Vault is sealed")
+
+	// ErrAlreadyInit is returned if the core is already
+	// initialized. This prevents a re-initialization.
+	ErrAlreadyInit = errors.New("Vault is already initialized")
+
+	// ErrNotInit is returned if a non-initialized barrier
+	// is attempted to be unsealed.
+	ErrNotInit = errors.New("Vault is not initialized")
+)
+
 // SealConfig is used to describe the seal configuration
 type SealConfig struct {
 	// SecretParts is the number of parts the secret is
@@ -22,6 +48,26 @@ type SealConfig struct {
 	SecretProgress int `json:"secret_progress"`
 }
 
+// Validate is used to sanity check the seal configuration
+func (s *SealConfig) Validate() error {
+	if s.SecretParts <= 0 {
+		return fmt.Errorf("must have a positive number for secret parts")
+	}
+	if s.SecretThreshold <= 0 {
+		return fmt.Errorf("must have a positive number for secret threshold")
+	}
+	if s.SecretThreshold > s.SecretParts {
+		return fmt.Errorf("secret threshold cannot be larger than secret parts")
+	}
+	return nil
+}
+
+// InitResult is used to provide the key parts back after
+// they are generated as part of the initialization.
+type InitResult struct {
+	SecretParts [][]byte
+}
+
 // Core is used as the central manager of Vault activity. It is the primary point of
 // interface for API handlers and is responsible for managing the logical and physical
 // backends, router, security barrier, and audit trails.
@@ -34,6 +80,16 @@ type Core struct {
 
 	// router is responsible for managing the mount points for logical backends.
 	router *Router
+
+	// stateLock protects mutable state
+	stateLock sync.RWMutex
+	sealed    bool
+
+	// unlockParts has the keys provided to Unseal until
+	// the threshold number of parts is available.
+	unlockParts [][]byte
+
+	logger *log.Logger
 }
 
 // NewCore is used to construct a new core
@@ -49,6 +105,7 @@ func NewCore(physical physical.Backend) (*Core, error) {
 		physical: physical,
 		barrier:  barrier,
 		router:   NewRouter(),
+		sealed:   true,
 	}
 
 	// Create and mount the system backend
@@ -62,34 +119,162 @@ func NewCore(physical physical.Backend) (*Core, error) {
 
 // HandleRequest is used to handle a new incoming request
 func (c *Core) HandleRequest(req *Request) (*Response, error) {
+	// TODO:
 	return c.router.Route(req)
 }
 
 // Initialized checks if the Vault is already initialized
 func (c *Core) Initialized() (bool, error) {
-	return false, nil
+	// Check the barrier first
+	init, err := c.barrier.Initialized()
+	if err != nil || !init {
+		c.logger.Printf("[ERR] core: barrier init check failed: %v", err)
+		return false, err
+	}
+	if !init {
+		c.logger.Printf("[INFO] core: security barrier not initialized")
+		return false, nil
+	}
+
+	// Verify the seal configuration
+	sealConf, err := c.SealConfig()
+	if err != nil {
+		return false, err
+	}
+	if sealConf == nil {
+		return false, nil
+	}
+	return true, nil
 }
 
 // Initialize is used to initialize the Vault with the given
 // configurations.
-func (c *Core) Initialize(config *SealConfig) error {
-	return nil
+func (c *Core) Initialize(config *SealConfig) (*InitResult, error) {
+	// Check if the seal configuraiton is valid
+	if err := config.Validate(); err != nil {
+		c.logger.Printf("[ERR] core: invalid seal configuration: %v", err)
+		return nil, fmt.Errorf("invalid seal configuration: %v", err)
+	}
+
+	// TODO: Remove restrict
+	if config.SecretParts != 1 {
+		return nil, fmt.Errorf("Unsupported configuration")
+	}
+
+	// Avoid an initialization race
+	c.stateLock.Lock()
+	defer c.stateLock.Unlock()
+
+	// Check if we are initialized
+	init, err := c.Initialized()
+	if err != nil {
+		return nil, err
+	}
+	if init {
+		return nil, ErrAlreadyInit
+	}
+
+	// Encode the seal configuration
+	config.SecretProgress = 0
+	buf, err := json.Marshal(config)
+	if err != nil {
+		return nil, fmt.Errorf("failed to encode seal configuration: %v", err)
+	}
+
+	// Store the seal configuration
+	pe := &physical.Entry{
+		Key:   coreSealConfigPath,
+		Value: buf,
+	}
+	if err := c.physical.Put(pe); err != nil {
+		c.logger.Printf("[ERR] core: failed to read seal configuration: %v", err)
+		return nil, fmt.Errorf("failed to check seal configuration: %v", err)
+	}
+
+	// Generate a master key
+	masterKey, err := c.barrier.GenerateKey()
+	if err != nil {
+		c.logger.Printf("[ERR] core: failed to generate master key: %v", err)
+		return nil, fmt.Errorf("master key generation failed: %v", err)
+	}
+
+	// Initialize the barrier
+	if err := c.barrier.Initialize(masterKey); err != nil {
+		c.logger.Printf("[ERR] core: failed to initialize barrier: %v", err)
+		return nil, fmt.Errorf("failed to initialize barrier: %v", err)
+	}
+
+	// Return the master key if only a single key part is used
+	results := new(InitResult)
+	if config.SecretParts == 1 {
+		results.SecretParts = append(results.SecretParts, masterKey)
+
+	} else {
+		// TODO: Support multiple parts
+		panic("unsupported")
+	}
+
+	return results, nil
 }
 
 // Sealed checks if the Vault is current sealed
 func (c *Core) Sealed() (bool, error) {
-	return true, nil
+	c.stateLock.RLock()
+	defer c.stateLock.RUnlock()
+	return c.sealed, nil
 }
 
 // SealConfiguration is used to return information
 // about the configuration of the Vault and it's current
 // status.
 func (c *Core) SealConfig() (*SealConfig, error) {
-	return nil, nil
+	// Fetch the core configuration
+	pe, err := c.physical.Get(coreSealConfigPath)
+	if err != nil {
+		c.logger.Printf("[ERR] core: failed to read seal configuration: %v", err)
+		return nil, fmt.Errorf("failed to check seal configuration: %v", err)
+	}
+
+	// If the seal configuration is missing, we are not initialized
+	if pe == nil {
+		c.logger.Printf("[INFO] core: seal configuration missing, not initialized")
+		return nil, nil
+	}
+
+	// Decode the barrier entry
+	var conf SealConfig
+	if err := json.Unmarshal(pe.Value, &conf); err != nil {
+		c.logger.Printf("[ERR] core: failed to decode seal configuration: %v", err)
+		return nil, fmt.Errorf("failed to decode seal configuration: %v", err)
+	}
+
+	// Check for a valid seal configuration
+	if err := conf.Validate(); err != nil {
+		c.logger.Printf("[ERR] core: invalid seal configuration: %v", err)
+		return nil, fmt.Errorf("seal validation failed: %v", err)
+	}
+	return &conf, nil
 }
 
 // Unseal is used to provide one of the key parts to
 // unseal the Vault.
 func (c *Core) Unseal(key []byte) (bool, error) {
+	c.stateLock.Lock()
+	defer c.stateLock.Unlock()
+
+	// TODO
 	return false, nil
 }
+
+// Seal is used to re-seal the Vault. This requires the Vaultto
+// be unsealed again to perform any further operations.
+func (c *Core) Seal() error {
+	c.stateLock.Lock()
+	defer c.stateLock.Unlock()
+	if c.sealed {
+		return nil
+	}
+	c.logger.Printf("[INFO] core: vault is being sealed")
+	c.sealed = true
+	return c.barrier.Seal()
+}