Patent Publication Number: US-2018034787-A1

Title: Data encryption key sharing for a storage system

Description:
BACKGROUND 
     Cyber attacks continue to grow more sophisticated and persistent. To combat threats and keep data safe, Information technology (IT) teams have to employ robust encryption, key management, and access controls. This is especially true for information held in storage environments, which can contain an organization&#39;s most vital assets. To secure storage, many organizations have been leveraging native encryption offerings from their storage vendors. The growing trend with “all flash” storage array deployments in enterprises pose particular challenges when encrypted data from host servers have to be stored in these arrays. Flash storage arrays offer high performance and capabilities like compression and deduplication for storage efficiency. With sophisticated encryption algorithms that extend beyond simple substitution ciphers, encrypted data tends not to compress as much, and tends to not yield as much reduction in storage, as when deduplication and/or compression are applied to unencrypted data. Many storage systems are available with deduplication and/or compression, for example in network attached storage (NAS or SAN). Yet, to supply unencrypted or plaintext data over a network to such a storage system is risky, and can result in a security breach. It is within this context that the embodiments arise. 
     SUMMARY 
     In some embodiments, a method for key sharing with a storage system, performed by a network device or security manager is provided. The method includes sharing a first key with a host system and sharing the first key with a storage system. The host system encrypts a file or data with the first key and sends the encrypted file or data to the storage system. The storage system decrypts the encrypted file or data with the first key, compresses the decrypted file or data, and re-encrypts the decrypted file or data. 
     Other aspects and advantages of the embodiments will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The described embodiments and the advantages thereof may best be understood by reference to the following description taken in conjunction with the accompanying drawings. These drawings in no way limit any changes in form and detail that may be made to the described embodiments by one skilled in the art without departing from the spirit and scope of the described embodiments. 
         FIG. 1  is a system block diagram showing a data security management system managing a shared first key for a host that encrypts data with the first key, and a storage system that decrypts the data with the first key, deduplicates and compresses the decrypted data, re-encrypts the data with a storage local second key and stores the second key encrypted deduplicated, compressed data in storage memory in accordance with some embodiments. 
         FIG. 2  depicts internal processes of the storage system, including decryption with the first key and encryption with the second key in accordance with some embodiments. 
         FIG. 3  is a system block diagram showing hosts directly communicating keys to a storage system, in a further embodiment of the system of  FIG. 1  without the data security management system in accordance with some embodiments. 
         FIG. 4  is a system diagram showing extended key sharing coordinated by a data security management system, with multiple hosts, multiple keys and multiple storage systems, in a further embodiment of the system of  FIG. 1  in accordance with some embodiments. 
         FIG. 5  is a system diagram showing transmission of both encrypted data and encrypted metadata between host and storage system, in an embodiment applicable to variations of  FIGS. 1-4  in accordance with some embodiments. 
         FIG. 6A  depicts a modified file system communicating with the data security management system in accordance with some embodiments. 
         FIG. 6B  depicts the host communicating with the data security management system, using messages in accordance with some embodiments. 
         FIG. 6C  depicts the data security management system intercepting a network packet sent by the host to the storage system, and parsing the header in accordance with some embodiments. 
         FIG. 7  is a flow diagram of a method for key sharing, which can be performed by a data security management system in cooperation with one or more hosts and one or more storage systems in accordance with some embodiments. 
         FIG. 8  is a system diagram depicting a secure volume manager encrypting data and encrypting metadata, for storage in accordance with some embodiments. 
         FIG. 9  is a flow diagram of a method for encrypting data and metadata, which can be practiced using the system depicted in  FIG. 8  and can also be practiced using the key sharing depicted in  FIGS. 1-7  in accordance with some embodiments. 
         FIG. 10  is an illustration showing an exemplary computing device which may implement the embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     For security reasons, it is desirable to send encrypted data over a network to a storage system, so that unencrypted data is not accessible on the network. And, for storage efficiency and storage density reasons, it is desirable to deduplicate and/or compress unencrypted data prior to storage. Also for security reasons, it is desirable to store encrypted data, not unencrypted or plaintext data, in storage memory. These preferences are addressed by various embodiments of key sharing for a storage system as disclosed herein. In common across many of these embodiments, a host encrypts data with a first key, and sends the encrypted data, e.g., over a network, to a storage system. The storage system decrypts the data, using the first key, and performs deduplication and/or compression on the unencrypted or decrypted data. Then, the storage system encrypts the resultant deduplicated and/or compressed data, with a second key that is local to that storage system, finally storing the data as deduplicated and/or compressed, and encrypted. Various embodiments thus avoid sending unencrypted data over a network, also avoid deduplicating encrypted data and compressing encrypted data, and finally avoid storing unencrypted data, hence satisfying the above preferences. A data security management system, which can be networked device, is disclosed herein as managing and sharing one or more keys for the host(s) and storage system(s) in various embodiments. 
       FIG. 1  is a system block diagram showing a data security management system  102  managing a shared first key  108  for a host  110  that encrypts data with the first key, and a storage system  116  that decrypts the data with the first key, deduplicates and compresses the decrypted data, re-encrypts the data with a storage local second key  120  and stores the second key encrypted deduplicated, compressed data in storage memory  118 . Each host  110  and each storage system  116  is equipped with one or more encryption/decryption modules  112 , which could be implemented in software executing on a processor, firmware, hardware or combinations thereof, as combined encryption and decryption, or separate encryption and decryption, etc. Each host  110  and each storage system  116  stores the shared first key  108 . Each storage system  116  has a deduplication module  114  and/or a compression module  116 , plus storage memory  118 , and memory in which the storage local second key  120  is stored. Deduplications module  114  and compression module  116  may be combined within module  115  in some embodiments as the illustration is meant to be an example and not limiting. Key  120  is local to the storage system  116 , for encryption and decryption of data stored in the storage memory  118 , and is not available to any of the hosts  110  in this embodiment. All components of the system could be implemented in hardware, firmware, software executing on one or more processors, or various combinations thereof, which may be virtualized and implemented using physical computing and memory resources, in some embodiments. 
     The data security management system  102 , which could be implemented in software executing on a processor, firmware, hardware or combinations thereof, has a policy manager  104  and a key manager  106 , along with memory in which the shared first key  108  is stored. There are multiple versions of how the shared first key  108  is sourced and distributed. In a single host system, the host  110  could generate or otherwise source the shared first key  108 , and send the shared first key  108  to the data security management system  102 , which distributes the shared first key  108  to one or more storage systems  116  in some embodiments. In a multiple host  110  system, one host  110  could generate or otherwise source the shared first key  108 , and send the shared first key  108  to the data security management system  102 . The data security management system  102  then sends the shared first key  108  to the other hosts  110  and to one or more storage systems  116 . In some embodiments, the data security management system  102  could generate or otherwise source the shared first key  108 , and send the shared first key  108  to one or more hosts  110  and one or more storage systems  116 . Further variations of sourcing and distribution for the shared first key  108  are readily devised in keeping with the teachings described herein. 
     The storage system  116  could be implemented using various storage technologies, and could include various types of storage memory  118  such as hard disks, flash memory or other solid-state storage, optical storage, tape, etc., and could include redundancy, error correction or other reliability enhancing technology, such as one or more levels of RAID (redundant array of independent disks or other storage devices). In one embodiment, the storage system  116  includes one or more encrypted logical units (LUNs) implemented as virtualized storage memory using physical storage and computing components. The storage system  116  has one or more encryption/decryption modules  112 , or equivalently, one or more encryption modules and one or more decryption modules, a deduplication module  114 , a compression module  116 , storage memory  118 , and memory for storing a shared first key  108  and a storage local second key  120 . The storage memory  118  could include one or more storage devices of various types as discussed above, in various configurations, and is not limited to a single device type or homogeneity. 
     In operation, the data security management system  102  coordinates distribution of a shared first key  108 . In one embodiment, the key manager  106  cooperates with the policy manager  104 , to distribute the shared first key  108  in accordance with one or more policies  122  of the policy manager  104 . Using the shared first key  108  that is generated or otherwise sourced by the host  110 , or received by the host  110  from the data security management system  102  in some embodiments, the host  110  encrypts data by way of the encryption/decryption module  112  of the host  110 . Following such encryption, the host  110  sends first key encrypted data  114  to the storage system  116 , for example via a network. Upon receipt of the first key encrypted data  114 , the storage system  116  uses an encryption/decryption module  112  and the shared first key  108  that is received by the storage system  116  from the data security management system  102 , or generated or otherwise sourced by the storage system  116  in some embodiments, to decrypt the first key encrypted data  114 . Next, the storage system  116  deduplicates the decrypted data, using the deduplication module  114 , or compresses the data using the compression module  116 , or both deduplicates and compresses the decrypted data, in various embodiments. After that, the storage system  116  uses either the same or another encryption/decryption module  112 , and the storage local second key  120 , to encrypt the deduplicated and/or compressed data, and stores the second key encrypted, deduplicated and or compressed data in the storage memory  118 . The above describes the host  110  writing data to the storage system  116 , for example using a write request. 
     For the host  110  to read data from the storage system  116 , the reverse path is followed. For example, the host  110  could send a read request to the storage system  116 . The storage system  116  reads the second key encrypted data from the storage memory  118 , and applies the storage local second key  120  and the encryption/decryption module  116  to decrypt the data. Then, the storage system  116  uses the compression module  116  and/or the deduplication module  114  to decompress and/or reconstitute the data. Finally the storage system  116  uses the shared first key  108  and the same or another encryption/decryption module  112  to encrypt the data, and sends the first key encrypted data  114  to the host  110 . The host  110  uses the shared first key  108  and the encryption/decryption module  112  of the host  110 , to decrypt the first key encrypted data  114 , and now has the desired read data in unencrypted or plaintext form. Other hosts  110  (in embodiments with more than one host  110 ) can use their own copy of the shared first key  108 , as managed by the data security management system  102 , to encrypt data and send data to the storage system  116 , or receive first key encrypted data  114  from the storage system  116  and decrypt the data. 
       FIG. 2  depicts internal processes of the storage system  116 , including decryption with the first key and encryption with the second key. Write data from the host  110  to the storage system  116  follows the write path  202  to the storage memory  118  (see  FIG. 1 ). Thus, first key encrypted data  114  written by the host  110  to the storage system  116  has decryption with the shared first key, deduplication and/or compression, encryption with the storage local second key, and storage of the first key decrypted, deduplicated and/or compressed, second key encrypted data in the storage memory  118 . 
     Read data from the storage system  116  follows the read path  204  from the storage memory  118 . Thus, the second key encrypted data in the storage memory is read from the storage memory  118  in a retrieval of the stored data, followed by decryption with the storage local second key, data decompression and/or data reconstitution, and encryption with the shared first key. The first key encrypted data  114  is then sent from the storage system  116  to the host  110 . 
       FIG. 3  is a system block diagram showing hosts  110  directly communicating keys  304 ,  306 ,  308  to a storage system  116 , in a further embodiment of the system of  FIG. 1  without the data security management system  102 . Variations could have just one host  110 , or many hosts  110 . The storage system  116  stores first keys  302 , for example in memory, and also has a storage local second key  120 , stored in memory. In one embodiment, the storage system  116  tracks which host  110  is sending read or write requests, and applies the appropriate first key  304 ,  306 ,  308  (e.g., first key A  304 , first key B  306  or first key N  308 ) to decrypt the first key encrypted data  114  sent by that host  110 , or encrypt data being sent to a host  110 . Other operations and modules, etc., are similar to those described in  FIGS. 1 and 2 . 
       FIG. 4  is a system diagram showing extended key sharing coordinated by a data security management system  102 , with multiple hosts  110 , multiple keys  304 ,  306 ,  308  and multiple storage systems  116 , in a further embodiment of the system of  FIG. 1 . Here, each host  110  sends a first key that is generated or otherwise sourced by that host  110 , to the data security management system  102 , which stores these in memory as first keys  302 . For example, one host  110  sends first key A  304 , another host  110  sends first key B  306 , and so on up through a host  110  that sends first key N  308 , to the data security management system  102 . The key manager  106  of the data security management system  102  coordinates the distribution of the first keys  302  to the various storage systems  116 , in accordance with the policy manager  104  and the policies  122 . In some embodiments, the host system(s) and/or the storage system(s) are key management interoperability protocol (KMIP) clients. 
     For example, to manage the keys, the key manager  106  could determine, in cooperation with the policy manager  104 , that the host  110  with the first key A  304  is writing to and reading from the left-most storage system  116  in  FIG. 4 . So, the key manager  106  could send the first key A  304  to that storage system  116 , which then uses the first key A  304  and the storage local key X  402  in a manner similar to that described with respect to  FIGS. 1 and 2 . Similarly, the key manager  106  could determine that the host  110  with the first key B  306  is writing to and reading from the middle storage system  116  in  FIG. 4 , and send the first key B  306  to that storage system  116 , which uses the first key B  306  and a storage local key Y  404 . And, the key manager  106  could determine that the host  110  with the first key N  308  is writing to and reading from the write-most storage system  116  in  FIG. 4 , and send the first key N  308  to that storage system  116 , which uses the first key N  308  and a storage local key Z  406 . In variations, hosts  110  could read and write to differing storage systems  116 , with appropriate distribution of first keys  302  by the key manager  106  in accordance with the policy manager  104 . For example, a host  110  could be allowed to write to one or more storage systems  116  and read from those or differing storage systems  116 , with appropriate distribution of first keys. Another embodiment has multiple first keys for each of one or more hosts, and each first key is specific to one or more blocks or chunks of write data for encryption by that host, and decryption by a targeted storage system  116 , with the first keys managed by the data security management system  102 . Read data is handled in a related manner. 
     In the embodiment shown in  FIG. 4 , each storage system  116  has a second key local to that storage system  116 . But, variations to this and further embodiments could be devised in which there are shared second keys, which could be managed by the storage systems, or managed by the data security management system  102 . 
       FIG. 5  is a system diagram showing transmission of both encrypted data and encrypted metadata between host  110  and storage system  116 , in an embodiment applicable to variations of  FIGS. 1-4 . In other systems, typically a host  110  may encrypt data and send encrypted data to a storage system  116 , but does not encrypt metadata such as filename, permissions, timestamp or other information about a file, when writing to the storage system  116 . In the embodiment shown in  FIG. 5 , the host  110  encrypts the data  504 , using the first key  502 , and sends first key encrypted data  508  to the storage system  116  for storage. Also, the host  110  encrypts metadata  506  relating to the data  504 , using the first key  502 , and sends first key encrypted metadata  510  to the storage system  116  for storage. Key management is performed as described for the data security management system  102  in various embodiments in  FIGS. 1-4 . In further embodiments, differing first keys could be used for encrypting the data and the metadata, or differing first keys could be used for block specific encryption. 
     For writing data from the host  110  to the storage memory  118  (see  FIG. 1 ), the storage system  116  uses the first key  502  to decrypt the first key encrypted data  508 , which is then deduplicated and/or compressed, followed by encryption using the storage local second key  120  as described above with reference to  FIGS. 1 and 2 . And, the storage system  116  uses the first key  502  to decrypt the first key encrypted metadata  510 , which is then deduplicated and/or compressed, followed by encryption using the storage local key  120 . In a variation, the storage system  116  has context aware information about the metadata, and does not apply deduplication or compression to the first key encrypted metadata  510  after decryption with the first key  502 , and only re-encrypts the decrypted metadata with the storage local key  120  prior to storage in the storage memory  118  (see  FIG. 1 ). 
     For reading data from the storage memory  118  to the host  110 , the reverse path is followed, as the storage system  116  decrypts the second key encrypted data retrieved from the storage memory  118 , using the storage local key  120 , followed by decompression and/or reconstitution of the data, and encryption using the first key  502 , with the storage system  116  sending first key encrypted data to the host  110 . Similarly, the storage system  116  decrypts the second key encrypted metadata retrieved from the storage memory  118 , using the storage local key  120 , followed by decompression and/or reconstitution of the metadata in embodiments where the metadata was deduplicated and/or compressed prior to storage. Finally the storage system encrypts the measured data, using the first key  502 , and sends first key encrypted metadata  510  to the host  110 . 
       FIGS. 6A-6E  show various mechanisms for determining which file or data from which host  110  uses which key for encryption by the host  110  and decryption by the storage system  116  to which the file or data is sent by the host  110  in the case of data write, or encryption by the storage system  116  and decryption by the host  110  that receives the file or data, in the case of data read. These mechanisms can be used in various embodiments of the system described with reference to  FIGS. 1-5 , so that one or more keys can be managed and distributed. In some embodiments, these mechanisms are used for determining, verifying, implementing or modifying portions of the policies  122  (see  FIG. 1 ) used by the policy manager  104  in the data security management system  102 . 
       FIG. 6A  depicts a modified file system  602  communicating with the data security management system  102 . Communication could be by messages, data access, request, etc. For example, the secure file system  602  could communicate to the data security management system  102  each time a file or data is written by the host  110  to a storage system  116 , and each time a file or data is requested to be read from a storage system  116  to the host  110 . In some embodiments, communication could be to initially establish usage of a storage system  116  by the host  110 , and again to announce changes.  FIG. 6B  depicts the host  110  communicating with the data security management system  102 , using messages  604 . These messages  604  could communicate as described above with reference to  FIG. 6A , but originate from the host  110  rather than from a file system, in some embodiments. 
     In some embodiments agents in the host  110  and the storage system  116  may facilitate communicating with each other. For example, an agent in the host  110  could access information in the file system, without actually requiring any modification of the file system in some embodiments. Communication could allow the storage system  116  to determine which key to use in some embodiments. Agents in the host  110  and the storage system  116  may facilitate communicating with the data security management system  102  in some embodiments. Communication among the agents and the data security management system  102  enables the data security management system  102  to determine which key or keys go where and how the keys are to be used in some embodiments. 
       FIG. 6C  depicts the data security management system  102  intercepting a network packet  612  sent by the host  110  to the storage system  116 , and parsing the header  608 . In this example, the header  608  has information about the payload  610 , which could be a file or data. By parsing the header  608 , using a parser  614 , the data security management system  102  can determine which host  110  sent the packet  612 , the destination storage system  116  for the packet  612 , and which key the storage system  116  should have. 
       FIG. 7  is a flow diagram of a method for key sharing, which can be performed by a data security management system in cooperation with one or more hosts and one or more storage systems. The method can be performed by one or more processors, for example processors in a data security management system, hosts and storage systems. In various embodiments, the data security management system is a network device, also referred to as a security manager or security device, and communicates with the host(s) and storage system(s) via a network. In an action  702 , the data security management system generates keys. In an action  704 , the data security management system shares the generated keys with one or more storage systems and one or more host systems, according to policies. 
     In an action  706 , each host encrypts data, using the key of that host, and sends the key encrypted data to a storage system. In an action  708 , each host encrypts metadata, using the key of that host, and sends the key encrypted metadata to a storage system. This could be the same or a differing storage system in various embodiments. In an action  710 , each storage system decrypts the data, using the first key, as shared by the host and/or by the data security management system. In an action  710 , each storage system can also decrypt the metadata, using the first key, as shared by the host and/or by the data security management system. 
     In an action  712  each storage system deduplicates and/or compresses the decrypted data and/or decrypted metadata. In an action  714 , each storage system encrypts deduplicated and/or compressed data and/or metadata, using a local storage key, and stores the local storage key encrypted, deduplicated and/or compressed data and/or metadata in storage memory. 
     In a further method, the majority of the above steps are reversed, for reading data and/or metadata from a storage system to a host. In further methods, subsets or variations of the above actions are applied to methods for a single host and a single storage system, with or without a data security management system, a method in which data is encrypted but metadata is not encrypted by the host, and a method in which individual blocks or chunks of data are associated with individual first keys for a storage system. Still further methods include a method in which second keys are managed by the data security management system, methods in which keys are generated by hosts, methods in which keys are generated by the data security management system, methods in which the keys are generated by the storage systems, and methods in which various mechanisms described above for communication among hosts, the data security management system and/or the storage system(s) are used for determining the sharing of the various keys. 
       FIG. 8  is a system diagram depicting a secure volume manager  808  encrypting data and encrypting metadata, for storage. This system can be used as shown, or in combination with an embodiment of the key sharing system shown in  FIGS. 1-7 . Particularly, one embodiment combines the system shown in  FIG. 5  and the system shown in  FIG. 8 , for a system that has key sharing and encryption and decryption of both data and metadata. Further embodiments combine the variations of key sharing systems shown in  FIGS. 1-4 , the encryption and decryption of both data and metadata of  FIG. 5 , and the secure data system of  FIG. 8 . 
     In  FIG. 8 , an application  802  (e.g., operating on a host  110  of  FIG. 1  or  FIGS. 3-7 ) produces a read request for data to be read from the storage  810 , or a write request, for data to be written to the storage  810  (e.g., storage system  116  and storage memory  118  in  FIG. 1 ). It is desired that the data and the metadata relating to the data (e.g., filename, permissions, timestamp, file size, file type, file owner, block identifiers, etc.) be sent in secure form to the storage  810 , for example over a network. The application sends the read request or the write request to a secure file system  804 . The secure file system  804  has access control, using guard points, etc., and uses the metadata in unencrypted form to determine whether or not to approve a read request or a write request. After verifying appropriate access control, the secure file system  804  sends the request to read or write a secure file through I/O (input/output) to the file system  806 , which then sends the request to the secure volume manager  808 . 
     The secure volume manager  808  has an encryption/decryption module  812 , and appropriate key(s). In one embodiment, keys are managed as described above with reference to  FIGS. 1-7  in a key sharing system. For the write request, the secure volume manager  808  performs encryption, i.e., encrypts the data and encrypts the metadata, and sends secure (encrypted) data and secure (encrypted) metadata to the storage  810 . For the read request, the secure volume manager  808  requests the secure data and the secure metadata from the storage  810 , and performs decryption, i.e., decrypts the encrypted data and decrypts the encrypted metadata received from the storage  810 . The secure volume manager  808  passes the decrypted data and the decrypted metadata up through the filesystem  806 , through the secure file system  804 , to the application  802 . The above processes can be performed by one or more processors, using system layers, for example an application layer, a secure file system layer, a file system layer, and a secure volume manager layer, as described below with reference to  FIG. 9 . Thus, only secure data and secure metadata, not unencrypted data and not unencrypted metadata, are sent over a network to storage  810 . In some embodiments the encrypted data and the encrypted metadata are handled in a combined flow, in other embodiments, these are handled in separate flows. 
     The above system solves multiple problems. A first problem is that, if the application  802  encrypted the metadata, the secure file system  804  would not have access to unencrypted metadata for use in access control and guard points. Also, a system administrator would not have access to unencrypted metadata to see file information. A second problem is that, if the application  802 , the secure file system  804  or the file system  806  encrypted the metadata, the metadata would not necessarily be aligned along 512 byte boundaries that the storage  810  prefers for decryption and compression as described above with reference to  FIGS. 1-7 . A third problem is that, if data is encrypted but metadata is not, and both of these are sent to storage  810 , the storage  810  sees only data blocks and does not have knowledge to understand that the encrypted data should be decrypted for compression but the unencrypted metadata should not be decrypted for compression. These problems are solved by having the secure volume manager  808  perform encryption, for both data and metadata being sent to storage  810 , and decryption, for both data and metadata being retrieved from the storage  810 , so that the storage  810  sees encrypted blocks of both data and metadata, aligned along the appropriate byte boundaries, and can correctly perform decryption and compression as described above. 
       FIG. 9  is a flow diagram of a method for encrypting data and metadata, which can be practiced using the system depicted in  FIG. 8  and can also be practiced using the key sharing depicted in  FIGS. 1-7 . The method can be practiced by one or more processors, in a secure data system. In an action  902 , a write request is passed from an application layer down to a secure file system layer. In a determination action  904 , it is determined whether the write request is approved by access control, at the secure file system layer. If the answer is no, the write request is not approved by access control, then the write request is denied, in an action  906 . If the answer is yes, the write request is approved by access control, and flow proceeds to the action  908 . In the action  908 , a request to write a secure file is passed from the secure file system layer through the file system layer to the secure volume manager layer. In an action  910 , data is encrypted and metadata is encrypted at the secure volume manager layer. The encrypted data and the encrypted metadata are sent to storage, in an action  912 . A related method for a read request is readily devised by passing and approving a read request in the above steps and applying decryption to encrypted data and encrypted metadata read from the storage, then passing the decrypted data and the decrypted metadata through to the application layer. 
     It should be appreciated that the methods described herein may be performed with a digital processing system, such as a conventional, general-purpose computer system. Special purpose computers, which are designed or programmed to perform only one function may be used in the alternative.  FIG. 10  is an illustration showing an exemplary computing device which may implement the embodiments described herein. The computing device of  FIG. 10  may be used to perform embodiments of the functionality for key sharing for a storage system, and/or encryption and decryption of both data and metadata, in accordance with some embodiments. The computing device includes a central processing unit (CPU)  1001 , which is coupled through a bus  1005  to a memory  1003 , and mass storage device  1007 . Mass storage device  1007  represents a persistent data storage device such as a floppy disc drive or a fixed disc drive, which may be local or remote in some embodiments. Memory  1003  may include read only memory, random access memory, etc. Applications resident on the computing device may be stored on or accessed via a computer readable medium such as memory  1003  or mass storage device  1007  in some embodiments. Applications may also be in the form of modulated electronic signals modulated accessed via a network modem or other network interface of the computing device. It should be appreciated that CPU  1001  may be embodied in a general-purpose processor, a special purpose processor, or a specially programmed logic device in some embodiments. 
     Display  1011  is in communication with CPU  1001 , memory  1003 , and mass storage device  1007 , through bus  1005 . Display  1011  is configured to display any visualization tools or reports associated with the system described herein. Input/output device  1009  is coupled to bus  1005  in order to communicate information in command selections to CPU  1001 . It should be appreciated that data to and from external devices may be communicated through the input/output device  1009 . CPU  1001  can be defined to execute the functionality described herein to enable the functionality described with reference to  FIGS. 1-9 . The code embodying this functionality may be stored within memory  1003  or mass storage device  1007  for execution by a processor such as CPU  1001  in some embodiments. The operating system on the computing device may be MS DOS™, MS-WINDOWS™ OS/2™, UNIX™, LINUX™, or other known operating systems. It should be appreciated that the embodiments described herein may also be integrated with a virtualized computing system implemented with physical computing resources. 
     Detailed illustrative embodiments are disclosed herein. However, specific functional details disclosed herein are merely representative for purposes of describing embodiments. Embodiments may, however, be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein. 
     It should be understood that although the terms first, second, etc. may be used herein to describe various steps or calculations, these steps or calculations should not be limited by these terms. These terms are only used to distinguish one step or calculation from another. For example, a first calculation could be termed a second calculation, and, similarly, a second step could be termed a first step, without departing from the scope of this disclosure. As used herein, the term “and/or” and the “/” symbol includes any and all combinations of one or more of the associated listed items. 
     As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Therefore, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. 
     It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. 
     With the above embodiments in mind, it should be understood that the embodiments might employ various computer-implemented operations involving data stored in computer systems. These operations are those requiring physical manipulation of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. Further, the manipulations performed are often referred to in terms, such as producing, identifying, determining, or comparing. Any of the operations described herein that form part of the embodiments are useful machine operations. The embodiments also relate to a device or an apparatus for performing these operations. The apparatus can be specially constructed for the required purpose, or the apparatus can be a general-purpose computer selectively activated or configured by a computer program stored in the computer. In particular, various general-purpose machines can be used with computer programs written in accordance with the teachings herein, or it may be more convenient to construct a more specialized apparatus to perform the required operations. 
     A module, an application, a layer, an agent or other method-operable entity could be implemented as hardware, firmware, or a processor executing software, or combinations thereof. It should be appreciated that, where a software-based embodiment is disclosed herein, the software can be embodied in a physical machine such as a controller. For example, a controller could include a first module and a second module. A controller could be configured to perform various actions, e.g., of a method, an application, a layer or an agent. 
     The embodiments can also be embodied as computer readable code on a tangible non-transitory computer readable medium. The computer readable medium is any data storage device that can store data, which can be thereafter read by a computer system. Examples of the computer readable medium include hard drives, network attached storage (NAS), read-only memory, random-access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes, and other optical and non-optical data storage devices. The computer readable medium can also be distributed over a network coupled computer system so that the computer readable code is stored and executed in a distributed fashion. Embodiments described herein may be practiced with various computer system configurations including hand-held devices, tablets, microprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers and the like. The embodiments can also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a wire-based or wireless network. 
     Although the method operations were described in a specific order, it should be understood that other operations may be performed in between described operations, described operations may be adjusted so that they occur at slightly different times or the described operations may be distributed in a system which allows the occurrence of the processing operations at various intervals associated with the processing. 
     In various embodiments, one or more portions of the methods and mechanisms described herein may form part of a cloud-computing environment. In such embodiments, resources may be provided over the Internet as services according to one or more various models. Such models may include Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). In IaaS, computer infrastructure is delivered as a service. In such a case, the computing equipment is generally owned and operated by the service provider. In the PaaS model, software tools and underlying equipment used by developers to develop software solutions may be provided as a service and hosted by the service provider. SaaS typically includes a service provider licensing software as a service on demand. The service provider may host the software, or may deploy the software to a customer for a given period of time. Numerous combinations of the above models are possible and are contemplated. 
     Various units, circuits, or other components may be described or claimed as “configured to” perform a task or tasks. In such contexts, the phrase “configured to” is used to connote structure by indicating that the units/circuits/components include structure (e.g., circuitry) that performs the task or tasks during operation. As such, the unit/circuit/component can be said to be configured to perform the task even when the specified unit/circuit/component is not currently operational (e.g., is not on). The units/circuits/components used with the “configured to” language include hardware—for example, circuits, memory storing program instructions executable to implement the operation, etc. Reciting that a unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. 112, sixth paragraph, for that unit/circuit/component. Additionally, “configured to” can include generic structure (e.g., generic circuitry) that is manipulated by software and/or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in manner that is capable of performing the task(s) at issue. “Configured to” may also include adapting a manufacturing process (e.g., a semiconductor fabrication facility) to fabricate devices (e.g., integrated circuits) that are adapted to implement or perform one or more tasks. 
     The foregoing description, for the purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the embodiments and its practical applications, to thereby enable others skilled in the art to best utilize the embodiments and various modifications as may be suited to the particular use contemplated. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.