Patent Application
20080165973
1. Field of the Invention
The present invention relates to the retrieval of valid key labels to have the access to encode data on a storage cartridge.
2. Description of the Related Art
Protecting and securing data is a primary concern that must be addressed when designing information management systems. It is common for data to be continually archived on various storage media, such as tape cartridges or optical disks. When archiving data on tape or other removable storage medium, one security concern is that the tape will be stolen to access the data it contains. Also, if the tape can be mounted into a tape drive through remote commands transmitted over a network, then there is a concern that someone may compromise the system, mount the tape or other storage medium in a drive, and then access the data.
Prior approaches to addressing these issues have included encrypting all or most of the data on the storage media. However, these approaches also have inherent drawbacks that include security weaknesses, implementation challenges and unwieldy complexity. For example, conventional solutions that store the data encryption key in unencrypted form on the same tape as the data it encrypts allow anyone with physical access to the tape to retrieve the data key from the tape and use it to decrypt the data. Furthermore, use of a single key to encrypt all of the data on one or more tape cartridges allows whoever has use of the key to decrypt all of the data comprising the tape cartridge, including data that doesn't belong to the user. Alternatively, multiple data keys can be stored on the tape drive, but key management becomes complicated when using multiple tape drives, as each tape drive has to be able to store all keys that are in use by all tape cartridges in the tape storage library. In addition, using multiple keys for one or more cartridges can lead to a proliferation of keys as the number of authorized users, tape drives, and tape cartridges grows. Conventional encryption systems also maintain the encryption and decryption keys in a central location, and the management and transfer of large numbers of such encryption keys can create additional issues.
One approach to addressing these issues is to encrypt the data keys and store them on the tape cartridge itself For example, when a tape drive requests an encryption key, a random symmetric data key (DK) is generated by an external key manager (EKM). Public/private cryptographic operations are then performed by the EKM to wrap the DK using a key encryption key (KEK), which is typically the public key of an asymmetric key pair. The wrapped data key, along with key label information about what private key is required to unwrap the symmetric key, forms an envelope generally known as an encryption encapsulated data key (EEDK). The EEDK is then typically stored in one or more places on the tape cartridge along with the data it encrypts. To facilitate key management, it is common to implement an encryption policy that assigns a key label, or alias, to a tape cartridge volume serial number (VOLSER) range encrypted by the EEDK. When an encrypted tape is to be read, the tape drive sends the EEDK to the EKM that contains its decryption key. The EKM determines from the EEDK's key label which private key from its keystore to use to unwrap the EEDK and recover the DK. Once the DK is recovered, it is then wrapped with a different key and sent to the tape drive, which decrypts the DK. The tape drive then decrypts the encrypted data on the tape cartridge using the decrypted DK. Similarly, a valid key label for the tape cartridge's VOLSER is retrieved if the tape is to be appended with encrypted data. Once retrieved, the same process is followed to decrypt the EEDK to retrieve the correct DK to encrypt the appended data. However, if multiple EKMs are implemented, each EKM has to be accessed to determine whether it produced the EEDK referenced by its key label.
A method, system and program are disclosed for the retrieval of key label codes enabling tamper resistant access to encrypted data in a removable storage medium, such as single tape storage cartridge. In selected embodiments, a data key (such as a symmetric AES key) is used to encrypt the data. The data key is encrypted or wrapped with one or more encryption keys (e.g., a public key from a public/private key pair) by an external key manager (EKM) to form one or more encryption encapsulated data keys (EEDKs). The EEDKs, which comprise a key label referencing the external key manager (EKM) that contains their decrypting key, may then be securely stored in the tape cartridge so that they need not be retained and somehow associated with the each tape cartridge by the tape driver or host system. The EEDK(s) are encrypted in a session encrypted data key (SEDK) and conveyed to the tape drive, where they are decrypted. The EEDK(s) are then stored in one or more places on the storage cartridge and the decrypted data key is used by the tape drive to encrypt data on the tape cartridge.
In selected embodiments, a tape library manager generates an updated key label list by querying one or more EKMs to collect the key labels they currently support. Once all key label updates have been received from the EKMs, the tape library manager purges its local key label list and refreshes the list with a global update of all current and valid key labels provided by the EKMs. A key label is then selected from the updated list and its associated EEDK is routed to the EKM containing the decryption key (e.g., the private key from the public/private key pair) to extract the data key it contains. The extracted data key can then be used to encode data on the tape cartridge.
In one embodiment, access to the encrypted data is changed without re-encrypting the underlying data, also known as rekey. The rekey process of changing the asymmetric Key Encrypting Key (KEK) that protects the Data Key (DK) stored on an already encrypted tape, thereby allowing different entities access to the data. In this embodiment, the original EEDK comprising the original key labels used to encrypt the tape cartridge is rewritten on the tape cartridge using the new EEDK comprising the new key labels. Thus, access to decrypt the tape cartridge is now only by the new EEDK comprising the new key labels.
Selected embodiments of the present invention may be understood, and its numerous objects, features and advantages obtained, when the following detailed description is considered in conjunction with the following drawings, in which:
a-b illustrate a user interface to a key label list management system used to update key label lists, and;
a-b illustrate a user interface to key label management system used to re-key a tape cartridge.
A method, system and program are disclosed for the retrieval of key label codes enabling access to encrypted data in a storage cartridge. In selected embodiments, a data key is encrypted or wrapped with one or more encryption keys by an external key manager (EKM) to form one or more encryption encapsulated data keys (EEDKs). The EEDK(s), which comprise a key label referencing the external key manager (EKM) that contain their decryption key, are then stored in one or more places on the storage cartridge and the decrypted data key is used by the tape drive to encrypt data on the tape cartridge. In selected embodiments, a tape library manager generates an updated key label list by querying one or more EKMs to collect the key labels they support. Once the key labels are collected, the existing list is purged and replaced with the new list of collected key labels. A key label is selected from the updated list and its associated EEDK is routed to the EKM containing the decryption key required to extract the data key it contains, which is then used to encode the data on the tape cartridge. In another embodiment, a tape library manager generates an updated key label list by querying one or more EKMs to collect the key labels they support. Once the key labels are collected, the existing list is purged and replaced with the new list of collected key labels. New key labels are selected from the updated list and its associated EEDK is routed to the EKM containing the decryption key required to extract the data key it contains, which is then used to re-encode the EEDKs on the tape cartridge. Thus, only allowing access to the encrypted data via the new key labels and the previous key labels access to the encrypted data is revoked.
Various illustrative embodiments of the present invention will now be described in detail with reference to the accompanying figures. It will be understood that the flowchart illustrations and/or block diagrams described herein can be implemented in whole or in part by dedicated hardware circuits, firmware and/or computer program instructions which are provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions (which execute via the processor of the computer or other programmable data processing apparatus) implement the functions/acts specified in the flowchart and/or block diagram block or blocks. In addition, while various details are set forth in the following description, it will be appreciated that the present invention may be practiced without these specific details, and that numerous implementation-specific decisions may be made to the invention described herein to achieve the device designer's specific goals, such as compliance with technology or design-related constraints, which will vary from one implementation to another. While such a development effort might be complex and time-consuming, it would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. For example, selected aspects are shown in block diagram form, rather than in detail, in order to avoid limiting or obscuring the present invention. In addition, some portions of the detailed descriptions provided herein are presented in terms of algorithms or operations on data within a computer memory. Such descriptions and representations are used by those skilled in the art to describe and convey the substance of their work to others skilled in the art. Various illustrative embodiments of the present invention will now be described in detail below with reference to the figures.
Referring to
Referring to
In the illustrated example, the EKM/host system 202 includes a host application (not shown), such as a backup program, that transfers data to the tape drive 218 to sequentially write to the tape cartridge 100, such as by using the Small Computer System Interface (SCSI) tape commands to communicate I/O requests to the tape drive 218, or any other data access command protocol known in the art. As will be appreciated, the EKM/host system ‘a’ 202 may be constructed from one or more servers (e.g., the EKM may reside on one server and any application which is reading and writing data to the drive may reside on another server). Similarly, multiple EKMs (e.g., EKM ‘a’ through EKM ‘n’) 202 may be implemented for redundancy, distribution of work load, or for other reasons. However implemented, the EKM/host(s) 202 includes data key generation functionality for generating a data key (DK) 206 for use in performing data encryption though this functionality may also be provided in the drive 218 or even externally to the system 200. In addition, the EKM/host 202 includes a public key crypto module 210 that is used to form a session encrypted data key (SEDK) 214 from the data key 206, and then to securely pass the SEDK 214 to the tape drive 218 as part of a secure key exchange. The public key crypto module 210 also securely encrypts the DK 206 to form one or more EEDKs 212 (as indicated by the stacked keys). In various embodiments, the public key crypto module 210 uses a predetermined public key encryption technique (such as RSA or ECC) to generate EEDK(s) 212 from DK(s) 206. For example, the public part of a public/private key pair that is retrieved from a key store 204 (which may or may not reside locally with EKM/host 202) may be used to wrap the data key 206 into its encrypted EEDK form. The encrypted EEDK form includes not only the encrypted data key DK itself, but also other structural information, such as a key label 208, which identifies the public/private key pair that is used to wrap the data key 206. Once a public key from the key store 204 is used to generate an EEDK 212, the identifying structural information in the EEDK 212 (e.g., the key label 208) can be later used by the key module 210 or EKM 202 as an index or reference to the public/private key pair in the key store 204 to retrieve the private key from the key store 204 when the EEDK 212 needs to be processed to unwrap the DK 206.
The tape drive 218 may connect with the host 202 through a direct interface (such as an SCSI, Fibre Channel (FCP), etc., in the case if the tape drive 218 is connected to the host 202) or may connect over a data channel or network 216 (such as a Local Area Network (LAN), Storage Area Network (SAN), Wide Area Network (WAN), the Internet, an Intranet, etc.). It will be appreciated that the tape drive 218 may be enclosed within the host system 202 or may be a standalone unit or in a tape library system (not shown), which may include one or more tape drives, one or more storage units to store multiple tape cartridges, and a mechanical system (commonly referred to as an accessor) to transfer the tape cartridges between the storage unit(s) and the tape drive(s). As illustrated, the tape drive 218 includes a memory circuit interface (IF) 224 for reading information from, and writing information to, the cartridge memory 102 of the data storage cartridge 100 in a contactless manner. In addition, a read/write servo drive system 228 is provided for reading information from, and writing information to, the rewritable tape media 108. The read/write servo drive system 228 controls the movement of a servo head (not shown) relative to the magnetic tape medium 108 by moving the magnetic tape medium 108 across the servo head at a desired velocity, and stops, starts and reverses the direction of movement of the magnetic tape.
A control system (or controller) 222 in the tape drive 216 communicates with the memory interface 224 and the read/write system servo drive 228. To receive commands and exchange information for operating the cartridge handling system 200, the controller 222 also acts as a host interface to communicate over one or more ports 220 with one or more external key management (EKM) subsystems 202 (such as a host computer, library or external key management appliance). In addition, a crypto module 226 and data encryption/decryption module 230 are provided in the tape drive 218 for securely encrypting and storing data to the tape cartridge 100 and for securely retrieving and decrypting data stored on the tape cartridge 100. In operation, the data encryption/decryption module 230 performs the actual data encryption and decryption (such as by using the Advanced Encryption Standard encryption algorithm) using a data key having any desired key length (e.g., 128 or 256-bit data key length), and may also perform other encoding functions, such as data compression and decompression and data buffering. The crypto module 226 controls the data encryption/decryption module 230 by securely exchanging data key (DK) 206b and its associated key label 208b using the SEDK 214b which is received from the EKM 202 (where it is originally generated as SEDK 214). At the crypto module 226, the DK 206b is extracted from the SEDK 214b, and is sent to the data encryption/decryption module 230 where it is used to encode/decode the input data stream. In addition, the crypto module 226 assembles, validates, distributes, stores and retrieves one or more associated EEDK(s) 212b (where the letter suffix “b” in the reference numeral indicates that the EEDKs 212 and 212b are logically identical, though physically distinct copies). While the modules 226, 230 may be implemented with any desired combination of hardware and/or software, the data encryption/decryption module 230 may be implemented with an ASIC or FPGA circuit, while the crypto module 226 may be implemented with one or more drive firmware modules that include a microprocessor and microcode stored in a code memory.
As described herein, the cartridge handling system 200 performs a variety of functions, including but not limited to, encrypting data to be stored on the cartridge 100 using a data key (such as an AES encryption key); using public key cryptography techniques to wrap the data key to form one or more encrypted data keys; writing and reading the encrypted data and encrypted data key(s) to and from the tape cartridge media; and unwrapping the encrypted data key such that the unwrapped key can decrypt the stored encrypted data. In this way, the cartridge handling system 200 provides a distributed key store which allows different user's data to be separately and uniquely encrypted on a single tape cartridge 100. For example, at least a first EEDK 212 is generated for local use by using a public key of the local key manager to wrap the data key 206, and the EEDK 212 is then transferred via the tape drive 218 (where it may be temporarily stored as 212b) for storage on the tape cartridge 100 at one or more predetermined locations, as indicated at 212c, 212d and 212e. As a result, the transferred EEDK 212b may be stored in the cartridge memory 102 and/or one or more non-user data areas of the tape media 108, such as a read-in area 232 or an end of tape area 234. Although only a single copy of the EEDK 210 is required to be stored on the tape cartridge 100, security and reliability are enhanced by using one or more non-user areas 232, 234 of the tape 108 to store multiple (e.g., three or more) copies of the EEDK 212 thereby allowing deletion of the EEDKs 212, 212b at the EKM 202 and tape drive 218. Since the only non-volatile copies of the EEDKs are stored within the tape cartridge 100, multiple copies of the EEDKs (212c, 212d, 212e, etc.) provide multiple ways to access the EEDK(s) and thus the data key 206 in the cases where one or more copies of the EEDKs cannot be read or otherwise processed due to errors or degraded media or drive conditions.
When a plurality of EEDKs 212 are generated from a single data key 206—such as when a second EEDK is generated for a remote user (e.g., a business partner) by using a public key of the remote user to wrap the data key 206—the plurality of EEDKs 212, and their associated key labels 208, are transferred via the tape drive 218 for storage on the tape cartridge 100 at one or more locations (as indicated by the copies of the EEDKs 212c, 212d and 212e that are stored in one or more non-user data areas 232, 234 of the tape media 108 and/or the cartridge memory 102). By storing multiple EEDKs on the tape cartridge 100 in specially designated locations (such as the cartridge memory 102 or outside of the tape's user data area), the tape cartridge 100 can have one EEDK wrapped for local use and another for remote exchange. In theory, any number of different EEDKs could be stored, provided there is storage space for them.
To illustrate how data may be securely encoded and stored on a removable tape cartridge that has not previously acquired its own encrypted data keys, reference is now made to the process flow depicted in
Otherwise, if it is determined in step 306 that the selected element is not to be encrypted, then the process is repeated beginning with the next element to be encrypted in step 304. Otherwise, a DK 206 is generated at the EKM 202 in step 310 and is then made available in encrypted form with its associated key label 208 to the tape drive 218 before the write process begins. To this end, a secure key exchange is used to transfer the DK 206 and its key label 208 in encrypted form to the tape drive 218 for purposes of enabling the tape drive encryption process.
While a variety of different encryption techniques may be used, an initial key generation process at the EKM 202 encrypts the DK 206 to form one or more EEDKs 212 using an encryption method, such as a pubic key cryptographic method in step 312. It is unimportant whether the encryption method is known outside of the EKM 202. In a selected embodiment, the EEDK 212 creation process in the EKM 202 uses asymmetric encryption by performing RSA 2048-bit encryption of the DK 206 with the public part of a public/private key pair to render the data key 206 within the EEDK 212 completely secure to any entity who does not possess the private part of the key pair. To associate the generated EEDK(s) 212 with the public/private key pair used to encrypt the DK 206, structural information (e.g., key label 208) about the public/private key pair is included in each generated EEDK 212 by the EKM 202 which can be extracted from the EEDK 212 for future access to the data key 206 and consequently the encrypted data itself.
At this time, a secure key exchange is established to encrypt the data key DK 206 with a session key (e.g., the public key from the tape drive 218), thereby generating a session encrypted data key (SEDK) 214 in step 316, which can be securely passed, along with the EEDK 212 and its associated key label 208, to the tape drive 218 in step 318. Once the EKM 202 sends the encrypted data keys to the tape drive 218, the DK 206, key label 208, and encrypted data key(s) 212, 214 may be discarded by the EKM 202 in step 318. As will be appreciated, there are several methodologies which may be used for secure key exchanges, including wrapping the DK 206 in a session key, though other techniques may be used, including but not limited to RSA, Diffie-Hellman (DH), elliptic curve Diffie Hellman (ECDH), Digital Signature Algorithm (DSA), elliptic curve DSA (ECDSA), etc. The session key may come from the tape drive 218 or the host 202.
Upon transfer to the tape drive 218, the EEDK(s) 212b and the SEDK 214b are stored in the crypto module 226. The tape drive 218 decrypts the SEDK 214b with its private session key to produce the DK 206b, which is used to set up the encryption hardware module 230. At any point after the encryption hardware module 230 is set up, the SEDK 214b may be discarded from the tape drive 218 in step 318. The tape drive also writes the EEDK(s) 212b to the tape cartridge 100 as part of set up or any point thereafter, and begins encrypting data using the extracted DK 206b in step 320. When writing the EEDK(s) 212b to the tape cartridge 100, the tape drive 218 stores multiple copies of the EEDK 212c-e in a plurality of locations, such as one or more non-user data areas 232, 234 of tape 108 and in the cartridge memory 102 in step 322. In selected embodiments, the EEDK(s) are written to the tape cartridge 100 before the encoding or writing of data since such writing may comprise many gigabytes. Also, by recording the EEDKs 212c-e first, the host system that encounters an error condition can retrieve some portion of the written encoded data by using the previously stored EEDK 212c-e for that encoded data. While the EEDK(s) 212b could be discarded from the tape drive after being written to the tape cartridge 100, they may be retained in the tape drive 218 in a volatile fashion for as long as the cartridge is loaded in the drive. Once the input data stream is encrypted and the tape drive 218 has written the encoded data to the tape 108, the tape drive 218 discards the DK 206b in step 322. Once the encoded data and EEDK(s) 212c-e are stored to the tape cartridge 100, the tape drive 218 discards the encoded data and the EEDK(s) 212b in step 322. The data encryption process then repeats itself, beginning with the next element to be decrypted in step 304.
An example of how data may be securely decoded and read from a removable tape cartridge will now be described with reference to the process flow depicted in
To enable the tape device hardware decryption and/or encryption process(es), a key exchange must occur in order to retrieve and decrypt the stored EEDKs 212c-e for purposes of extracting the correct decryption data key. However, when the data keys are not retained or stored on the tape drive 218 or the EKM 202, the EEDKs 212c-e must be used to reacquire the data key 206 at the EKM 202, which then securely transfers the DK 206 to the tape drive 218. For example, after the tape cartridge 100 is loaded and the EEDKs 212c-e are stored as EEDK(s) 212b in the crypto module 226 of the tape drive 218, the EEDK key labels are read to determine which EKM 202 generated them. Once determined, the EEDK(s) 212b are sent to the appropriate EKM 202 in step 412. Once the EEDK(s) 212b are transferred to the appropriate EKM 202, the EKM 202 determines their validity by extracting key label 208 information from the EEDK 212 and searching the key store 204 for a match, in which case the associated private key is output from the key store 204 and used to decrypt the EEDK 212, thereby extracting the data key DK 206 in step 414. The data key DK 206 is then securely wrapped in the tape drive's session key to generate the session encrypted data key SEDK 214 in step 416. Using any desired secure key exchange protocol, the EKM 202 passes the SEDK 214 to the tape drive 218 where it is stored as the SEDK 214b, at which time the EKM 202 discards the SEDK 214 in step 418. The tape drive 218 then decrypts the SEDK 214b with its private session key to produce the DK 206b, which is used to set up the decryption hardware module 230 in step 420. Once again, the tape drive 218 can discard the SEDK 212b at any point after the decryption hardware module 226 is set up, even before the stored data is decrypted. Continuing in step 420, the decryption hardware module 230 decodes the encrypted data element, and when decoding is completed, the process repeats, beginning with the next data element to be decrypted in step 404.
As illustrated in
When the EEDKs 212c, 212d are stored in non-user areas, the data key wrapping technology described herein may be used to change access to the encrypted data records 510 without re-encrypting the underlying data. By changing the access to the encrypted data key as described in greater detail herein, a variety of additional cartridge control features are provided, such as adding an EEDK to the cartridge, re-keying a cartridge, and shredding a cartridge. In particular, a DK can be encrypted with a first wrapping key (e.g., a public key from a public/private key pair) to form a first EEDK and then generating a first encryption policy comprising a first key label further comprising a first key mode. Subsequently, additional access to the DK can be provided by encrypting the DK with a second wrapping key to form a second EEDK and by generating a second encryption policy comprising a second key label further comprising a second key mode. With this approach, and by storing the new EEDK's outside of the user data area of the tape volume, multiple users can be added and enabled to access the encrypted data without re-encrypting the data. It will therefore be apparent that parallel access to the DK 206 (and therefore the data on the tape) is provided to anyone possessing the necessary unwrapping key (e.g., the private key from the public/private key pair) associated with any of the EEDK structures stored on the cartridge.
Another cartridge control feature is that a cartridge can be re-keyed when the KEK used to encrypt the EEDK expires or to change user access by removing a first user and adding a second user. This may be accomplished by decoding a first EEDK on the cartridge using an appropriate unwrapping key to extract the underlying data key DK, re-wrapping the DK using a different wrapping key (e.g., a new public key from a public/private key pair that belongs to a second user) to generate a new EEDK with a new key label, and re-storing the new EEDK back on the tape to overwrite the first EEDK. The result is that access is removed for anyone who previously could decode the first EEDK, while enabling access for anyone who could decode the new EEDK, all without having to re-write the data and encrypt it with a different data key.
Yet another cartridge control feature is that cartridge data access can be permanently prevented, effectively “shredding” the cartridge data. This may be accomplished by deleting or erasing the EEDK structures from the tape. Since the EEDK structures are the only repository for the data key needed to decrypt the cartridge data, the data may never be decrypted. Erasing the EEDK structures is much faster (on the order of 2-3 minutes versus 1-2 hours) and actually more secure then erasing all the data from the tape. Another advantage is that the wrapping and unwrapping keys do not need to be deleted from the key store to prevent readability of the tape, since the EEDK(s) have been deleted. Also, EEDK erasure can be performed more securely (e.g., using multiple erase passes with random patterns), more easily and more quickly then a secure erase of all encrypted data.
To extract a data key from the EEDK 618a (upon its subsequent receipt), the generated EEDK 618a includes structural information (such as key label 610a referencing the key encrypting key 620) that can be used to reference or lookup the key encrypting key 620 and its corresponding private key in the key store 620 that can be used to decrypt the received EEDK. In addition or in the alternative, the key store 620 stores information identifying the EEDKs generated by the host 602 so that the identifying information is associated (e.g., by using a table) with the public key used by the host to generate the EEDK. Finally, the host 602 includes a host controller 604 that handles I/O requests for directing a data input stream 606 to the tape drive 622. Once the DK 608a, KL 610a, and encrypted data keys 614a, 618a are used, they may be discarded from the host 602, as indicated by the dashed lines in
At the tape drive 622, the received SEDK 614b is stored and decrypted by the session key 624 to generate a local copy of the DK 608b, all under control of the tape drive controller 626. The DK 608b is then combined in an encryption circuit 628 with the input data stream 606 from the host 602, thereby generating an encrypted data stream 630 that is stored in the tape media 634. In addition, the received EEDK(s) 618b and their associated KLs 610b are forwarded to the storage device 632 where they are collectively stored to one or more locations 618c, 610c in the non-user data portion of the tape 634, and to predetermined location(s) 618d, 610d in the cartridge memory 636. Once the DK 608b and encrypted data keys 614b, 618b are processed at the tape drive 622, they may be discarded, as indicated by the dashed lines.
Upon receiving the EEDKs for a storage device 632 (at block 714), the tape drive controller 626 writes (at block 716) the encrypted data keys (EEDKs) to the storage device 634 and then discards the EEDKs. In addition, once the session encrypted data key (SEDK) is received at the tape drive (block 718), the tape drive controller 626 decrypts the SEDK to extract the data key using the tape drive private session key that corresponds to the public session key, and then uses the extracted DK 608 to encode data being written to the storage device (at block 720). After the data is encoded and stored, the DK and SEDK are discarded and the encoded data is transmitted to the storage device 632 (at block 722). When the EEDKs are received at the storage device (block 724), they are separately stored in multiple locations in the storage device, such as the cartridge memory and the non-user data area of the tape (block 726). In selected embodiments, the EEDK(s) are written to the storage device 632 prior to storing the encrypted data on the storage device (block 728).
Once it has been determined in step 816 that all key label updates have been received from the EKMs, the tape library manager purges its local key label list in step 818 and refreshes the list with a global update of all current and valid key labels provided by the EKMs. The refreshed key label list is then displayed in step 820 showing available and unique key labels. If it is determined in step 822 to perform additional key label update action, then the process is repeated beginning with step 802. Otherwise, key label update actions end in step 824.
a-b show an encryption policy user interface screen 902 as implemented in a web browser to update key label lists in accordance with an embodiment of the invention. In this embodiment,
Valid key labels 920 are displayed in a drop-down window and include key labels “XxXx_a”, “XxXx_b” and “XxXx_c”. In one embodiment, the data on the tape cartridge is to be encrypted and a previously generated key label needs to be specified to reference its corresponding EKM, which will generate the required data key for encryption. In this embodiment, the current list of key labels 922 may or may not contain the key labels referencing the EKM required to encrypt the VOLSER range depicted in windows 906, 910. Similarly, key label ‘2’ 924 of the VOLSER range displayed in windows 906, 910 is currently blank in window 926, key mode ‘2’ 928 is currently unchosen as displayed in window 930, and valid key labels 932 are not currently displayed.
b similarly depicts the encryption policy user interface screen 902 after the key label list has been purged and refreshed. The encryption user interface screen 902 comprises a beginning VOLSER 904 displayed in window 906 and an ending VOLSER 908 displayed in window 910. After the key label list has been refreshed, key label ‘1’ 912 of the VOLSER range displayed in windows 906, 910 now shows “XxXx_c” in window 934 as a valid and current choice from the valid key label 938 drop down window. Key mode ‘1’ 916 is now set to ‘clear’ as displayed in window 936. Previously selected key labels 934 have been updated as described in greater detail herein and are displayed in a drop-down window and include key labels “XxXx_a”, “XxXx_c”, “YyYy_d”, “YyYy_f”, and “YyYy_g”. The updated list of key labels 938 signify that previously displayed key label “XxXx_b”, and its related private key, is no longer resident on an associated EKM. Conversely, key labels “YyYy_d”, “YyYy_f”, and “YyYy_g” have been added to the list, and may have been generated by the same EKM that generated key labels “XxXx_a”, “XxXx_c”. Alternatively, key labels “YyYy_d”, “YyYy_f”, and “YyYy_g” may have been generated by a different EKM. Similarly, key label ‘2’ 924 of the VOLSER range displayed in windows 906, 910 now shows “YyYy_g” in window 940 as a valid and current choice from the valid key label 944 drop down window (not show). Likewise, key mode ‘2’ 928 is now set to ‘clear’ as displayed in window 942.
a-b show an encryption policy user interface screen 902 as implemented in a web browser to re-key a tape cartridge in accordance with an embodiment of the invention. In selected embodiments, the data key wrapping technology described herein may be used to change access to encrypted data without re-encrypting the underlying data. By changing the access to the encrypted data key, a variety of additional cartridge control features are provided, such as adding an EEDK to the cartridge, re-keying a cartridge, and shredding a cartridge. For example, when the DK is encrypted with a first wrapping key (e.g., a public key from a public/private key pair) to form a first EEDK, additional access to the DK can be provided by encrypting the DK with a second wrapping key to form a second EEDK.
In this embodiment,
As described in greater detail herein, multiple EEDK structures are created on the cartridge by using different KEKs to wrap the same underlying data key DK. As a result, parallel access to the DK (and therefore the data on the tape) is provided to anyone possessing the necessary unwrapping key (e.g., the private key from the public/private key pair) associated with any of the EEDK structures. In this figure, the new key label window 1036 is opened to create a new key label ‘1’ 920, which is entered in window 1038 as “ZzZz_a”. Similarly, a new key label window 1042 is opened to create a new key label ‘2’ 924, which is entered in field 1038 as “ZzZz_b” and its corresponding new key mode ‘1’ is likewise selected as “clear” in window 1046.
The current key label ‘1’ displayed in window 914 references the EKM that holds the private key required to decode a first EEDK on the cartridge, which results in the extraction of the underlying data key DK. The underlying DK is then re-wrapped using a different wrapping key (e.g., a new public key from a public/private key pair) to generate a new EEDK and a corresponding new key label ‘1’ displayed in window 1038. The new EEDK is then written back on the tape to overwrite the first EEDK. The result is that access is removed for anyone who previously could decode the first EEDK, while enabling access for anyone who could decode the new EEDK, all without having to re-write the data and encrypt it with a different data key.
b similarly depicts the rekey user interface screen 1002 after the key label list has been purged and refreshed after new key labels ‘1’ and ‘1’ have been respectively entered in windows 1038 and 1044 After the key label list has been refreshed, key label ‘1’ “ZzZz_a” in window 1048 as a valid and current key label in the previously selected key labels 1052 drop down window. Key mode ‘1’ 916 is now set to ‘clear as displayed in window 1050. Valid key labels 1052 have been updated as described in greater detail herein and are displayed in a drop-down window and now include key labels “XxXx_a”, “YyYy_d”, “YyYy_f’, and the newly created key labels “ZzZz_a”, and “ZzZz_b”. The updated list of key labels 1050 signify that key labels “XxXx_c” and “YyYy_f’, as well as their related private keys, are no longer resident on their associated EKMs. Conversely, key labels “ZzZz_a”, and “ZzZz_b” have been added to the list, and may have been generated by the same EKM that generated key labels “XxXx_a”, “YyYy_d”, and “YyYy_f”. Alternatively, key labels “ZzZz_a”, and “ZzZz_b” may have been generated by a different EKM. Similarly, new key label ‘2’ 924 now shows “ZzZz_b” in window 1054 as a valid and current choice from the valid key label 1058 drop down window (not shown). Likewise, key mode ‘2’ 928 is now set to ‘default’ as displayed in window 1056.
The foregoing description has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification and example implementations provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
