Secure Recovery of Security Credential Information

A system includes a shard generation circuit configured to create shards from a security credential, and to recreate the security credential from the shards. The system includes a secret generation circuit configured to create secrets from a shard and to recreate the shard from a subset of the secrets, and store at least one of secrets in a location. The system includes another secret generation circuit configured to create secrets from another shard, recreate the other shard of the shards, and store at least one the shards in another, different location.

FIELD OF THE INVENTION

The present disclosure relates to electronic data storage and, more particularly, to secure recovery of security credential information.

BACKGROUND

Data erasure of software defined storage (SDS) information at the storage level can be difficult to achieve. Ensuring that data can be securely destroyed in an SDS implementation can be difficult to achieve. The challenge is that the system is designed to specifically overcome the loss of data. The system may include several storage devices assembled into a cluster. A well accepted method of erasing data is to use a cryptographic erase. This may involve encrypting data that is written onto a storage device and then securely deleting the key. A common issue in cryptographic erase is how to recover the storage encryption key if the storage encryption key is accidentally destroyed.

There are many instances where storing a security credential is problematic. A security credential may be stored so as to provide a backup in case an erase of the credential was made accidentally, wherein such an erase might otherwise have been intended to perform, for example, a secure erase. Take as an example, use of encryption keys to protect the contents of a storage medium. To perform a cryptographic erasure, all copies of the data encryption key must be destroyed. However, many users may be worried that accidental destruction of the key would result in the lack of access to the data on the encrypted medium. Consequently, copies of the encryption key might be stored elsewhere. However, storing additional keys in other locations might itself present a security threat.

Embodiments of the present disclosure may address one or more of these challenges with improved key restoration techniques.

DETAILED DESCRIPTION

Embodiments of the present disclosure include methods for reconstitution of security credentials. Such credentials may be used, for example, for securing data storage. The intentional deletion of such credentials may be used in a secure erase process. Embodiments of the present disclosure may utilize multiple types of credentials to reconstitute the original security credential. As can also be seen in the discussion below, this may create different distribution mechanisms that provide some distinct advantages.

By using threshold encryption, a single security credential can be split into multiple parts. The parts can either be made up of derivatives of the original, e.g., sharding, or used to derive distinctly different values, e.g., Shamir's Secret Sharing Scheme. If a simple sharding method is used, all of the derivatives or shards may be required to generate the original. In secret sharing schemes, only a subset of the derivatives or secrets may be required to generate the original. Therefore, if N derivatives of the original data are created, then for a given scheme, TNmay denote how of those N derivatives that may be needed to reconstitute the original data. In the case of simple sharding, the number of derivatives is equal to the number required to reconstitute, e.g., N=TN. In a secret sharing scheme, the number of required derivatives to reconstitute the original data can be less than or equal to the total number of derivatives that are generated, e.g., N≥TN.

Embodiments of the present disclosure may include an apparatus. The apparatus may include a shard generation circuit, a first secret generation circuit, and a second secret generation circuit. The shard generation circuit, first secret generation circuit, and second secret generation circuit may be implemented by analog circuitry, digital circuitry, control logic, instructions for execution by a processor, digital logic circuits programmed through hardware description language, application specific integrated circuits, field programmable gate arrays, programmable logic devices, or any suitable combination thereof, whether in a unitary device or spread over several devices. Moreover, one or more of these circuits may be implemented in a single or multiple components.

The shard generation circuit may be configured to create shards from a security credential. As discussed above, when N=TN, simple sharding may be used, wherein all shards are needed to reconstitute the original security credential. A shard may include any suitable derivative of a security credential that, when all or a sufficient number of such shards are available, the security credential may be reconstituted or recreated. The shards may be implemented in any suitable information representation. The security credential may include any suitable information for authentication, such as a cryptographic key that is symmetric or asymmetric, or public or private, or a cryptographic hash, password, or passcode. The shard generation circuit may be configured to later recreate the security credential from the plurality of shards that were generated. The shard generation circuit may recreate the security credential by having access to all of the shards that were generated.

The first secret generation circuit may be configured to create a plurality of first secrets from a first shard of the shards generated by the shard generation circuit. The first secret generation circuit may be configured to later recreate the first shard of the plurality of shards from a subset of the plurality of secrets. The secrets may be implemented in any suitable information representation. A secret may include any suitable derivative of a security credential that, when all or a sufficient number of such shards are available, the security credential may be reconstituted or recreated. The first secret generation circuit may be configured to store at least one of the plurality of first secrets in a first location.

The second secret generation circuit may be configured to create a plurality of second secrets from a second shard of the plurality of shards, and to later recreate the second shard of the plurality of shards from a subset of the plurality of second secrets. The second secret generation circuit may be configured to store at least one of the plurality of second secrets in a second location. The second location in a different machine than the first location.

In combination with any of the above embodiments, the first secret generation circuit may use a threshold encryption P≥TPfunction, wherein the encryption generates P secrets, and a threshold number, TP, of those secrets may be needed to reconstitute or reconstruct the original shard from which the secret generation circuit generated the secrets.

In combination with any of the above embodiments, the first secret generation circuit may use a threshold encryption Q≥TQfunction, wherein the encryption generates Q secrets, and a threshold number, TQ, of those secrets may be needed to reconstitute or reconstruct the original shard from which the secret generation circuit generated the secrets. In various embodiments, the threshold encryption functions may be different between the generation circuits, and P and Q may be different numbers.

In combination with any of the above embodiments, the shard generation circuit may be configured to destroy the security credential after creation of the plurality of shards as part of a secure erase of data protected by the security credential.

In combination with any of the above embodiments, the second location may be a remote location to the system, and the second secret generation circuit may be further configured to store at least a second one of the plurality of second secrets in a third location, wherein the third location a remote location to the system and in a different machine than the second location.

In combination with any of the above embodiments, the first location may be local to the system.

In combination with any of the above embodiments, the plurality of first secrets may be independent of a machine on which the secrets reside.

In combination with any of the above embodiments, the plurality of second secrets may be dependent upon a machine on which the secrets reside.

In combination with any of the above embodiments, the apparatus may include an encryption circuit configured to encrypt the plurality of first secrets. The encryption circuit may be configured to decrypt encrypted first secrets. The encryption circuit may be implemented by analog circuitry, digital circuitry, control logic, instructions for execution by a processor, digital logic circuits programmed through hardware description language, application specific integrated circuits, field programmable gate arrays, programmable logic devices, or any suitable combination thereof, whether in a unitary device or spread over several devices.

In combination with any of the above embodiments, the encryption circuit may be configured to store the plurality of first secrets as encrypted on the system, and to provide the plurality of second secrets to the second location and a third location.

In combination with any of the above embodiments, the first secret generation circuit may be configured to store the plurality of first secrets as encrypted on the system. In combination with any of the above embodiments, the second secret generation circuit may be configured to provide the plurality of second secrets to the second location and a third location.

In combination with any of the above embodiments, the encryption circuit may be further configured to apply a different asymmetric encryption credential to each of the plurality of first secrets to encrypt each of the plurality of first secrets.

In combination with any of the above embodiments, a private asymmetric encryption credential corresponding to a public asymmetric encryption credential used to encrypt at least one of the plurality of the first secrets may be stored on a remote machine.

In combination with any of the above embodiments, the encryption circuit may be further configured to apply a first asymmetric encryption credential to a first one of the first secrets to encrypt the first one of the first secrets, and to apply a second asymmetric encryption credential to a second one of the first secrets to encrypt the second one of the first secrets. A first private key corresponding to the first asymmetric encryption credential may be stored on a first remote location. A second private key corresponding to the second asymmetric encryption credential may be stored on a second remote location. The second remote location may be different than the first remote location.

In combination with any of the above embodiments, the asymmetric encryption credentials to encrypt the first secrets may be stored internally to the apparatus.

In combination with any of the above embodiments, the security credential might not be stored remotely outside of the system.

In combination with any of the above embodiments, the shard generation circuit may be further configured to require regeneration of the first shard created as a server-independent shard and regeneration of the second shard created as a server-independent shard in order to recreate the security of shards from a security credential.

In combination with any of the above embodiments, the first secret generation circuit may be further configured to recreate the first shard of the plurality of shards only when a minimum number of the subset of the plurality of secrets are presented.

In combination with any of the above embodiments, the first secrets may be stored internally to the system and are device or server-independent.

In combination with any of the above embodiments, the second secrets may be stored externally to the system and are device or server-dependent.

In combination with any of the above embodiments, internally stored secrets may be only decryptable with a locally provided device. The device may be, for example, a smart card.

In combination with any of the above embodiments, the shard generation circuit may be configured to erase the security credential after creating the plurality of shards.

In combination with any of the above embodiments, the shard generation circuit may be configured to erase plurality of shards after recreating the security credential. This may be part of a secure erase.

In combination with any of the above embodiments, the first secret generation circuit may be configured to erase the first shard after creating the plurality of first secrets.

In combination with any of the above embodiments, the first secret generation circuit may be configured to erase the plurality of first secrets after recreating the first shard. This may be part of a secure erase.

In combination with any of the above embodiments, the second secret generation circuit may be configured to erase the plurality of second secrets after storing the plurality of second secrets in the second location. This may be part of a secure erase.

In combination with any of the above embodiments, secrets may be stored externally to the apparatus and encrypted secrets may be stored internally to the apparatus. Public keys may be used to perform the encryption. Public keys may be stored on the apparatus. The same public keys may be used to encrypt secrets for multiple apparatuses. Private keys to decrypt secrets may be stored externally. The private keys may be used to thus decrypt secrets for multiple apparatuses. Therefore, in this example, the private key is independent of the apparatus and tied to the owner of that key. This may be considered a device-independent or server-independent zone. However, secrets stored externally to the apparatus may be provided back to the apparatus for deletion. The secret for a given apparatus cannot be used on other apparatuses. This may be considered a device-dependent zone or server-dependent zone. For a given shard, at least one secret may be stored in a device-dependent zone and at least one secret may be stored in a device-independent zone.

FIG. 1is an illustration of a process for generating a distributed secret for a security credential, according to embodiments of the present disclosure.

As shown inFIG. 1, a security credential102is provided to a system100. System100may be a threshold encryption system. System100may include a processor (not shown) and a machine-readable, non-transitory medium (not shown). The medium may include instructions that, when loaded and executed by the processor, may cause system100to perform the functionality as described herein. Moreover, the functionality described herein may be implemented in any suitable manner, such as by analog circuitry, digital circuitry, control logic, instructions for execution by a processor, digital logic circuits programmed through hardware description language, application specific integrated circuits (ASIC), field programmable gate arrays (FPGA), programmable logic devices (PLD), or any suitable combination thereof, whether in a unitary device or spread over several devices.

System100may be configured to convert a security credential102using threshold encryption function circuit104.

Security credential102may include any suitable information for authentication. Security credential102may include, for example, a cryptographic key. The key may be symmetric or asymmetric, and public or private. In other cases, security credential102may include, for example, a cryptographic hash, password, or passcode.

Function circuit104may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices.

Function circuit104may be used for use cases wherein N=TN. As discussed above, when N=TN, simple sharding may be used, wherein all shards are needed to reconstitute the original security credential. Function circuit104may be configured to convert security credential102into multiple shards 1 (108A) through N (108N). Although a shard is shown as the derivative of security credential102, any suitable derivative of security credential102may be used. Function circuit104may be performed in such a way that the number of shards created by function circuit104is equal to the number of shards required to reconstitute security credential102. Therefore, if N derivatives are created by the application of function circuit104security credential102, and TNderivatives are needed to reconstitute security credential102, then N=TN. Function circuit104may perform this in any suitable manner. Function circuit104may perform this by splitting an initial copy of security credential102into subsets of the original data by using filters to generate shards108A-108N. Once shards108A-108N are created, the original copy of security credential102may be completely destroyed by, for example, being overwritten.

Next, threshold encryption P≥TPfunction circuit110and threshold encryption Q≥TQfunction circuit114may be configured to create derivatives from each of shards108A,108N. More functions, not shown, may be used to create derivates from the intervening shards between shards108A,108N. Each such function may have its own quantity of derivates created (such as P or Q) and corresponding threshold values (such as TPor TQ). Function circuits110,114and other functions not shown for creating derivatives from shards108may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices. Function circuits110,114and other functions not shown for creating derivatives from shards108may create derivatives such that fewer derivatives, given by T, are needed to reconstitute the original input. For function circuits110,114, the original input is given by P and Q, respectively. Thus, function circuits110,114may be referred to as P≥TPand Q≥TQ, respectively. Function circuit110may be configured to generate a quantity (P) of secrets112A-112P from shard108A. Similarly, function circuit114may be configured to generate a quantity (Q) of secrets116A-116Q from shard108N. Other functions not shown for creating derivatives from shards108may similar quantities of secrets from respective shards108that are greater than the number of derivatives needed to reconstitute the respective shard108. Function circuits110,114may use, for example, Shamir's Secret Sharing Scheme to generate the secrets from the shards. The secrets may be implemented in any suitable information representation. The actual value for P or Q, or for the other functions not shown, can differ with each function. Furthermore, P, Q, and T can be different for different instances or applications of a given function.

Thus, P secrets112may be generated for shard108A, and Q secrets116may be generated for shard108N. Not shown are secrets generated for each of the intervening shards108(not shown). Secrets112,116, and those not shown may be considered to be local secrets or external secrets. A local secret may be stored locally to system100for retrieval upon reconstitution of security credential102. An external secret may be stored externally to system100for retrieval upon reconstitution of security credential102. Secrets112,116, and those not shown may be stored in any suitable manner.

In one example, secrets112,116, and those not shown may be distributed securely to a remote location using a secure communications channel. Each of secrets112,116, and those not shown that are exported may sent to a different remote location. For example, secret116A may be sent to a remote location 1124A. Furthermore, external secret116Q may be sent to remote location124Q. Local copies of secrets116A-116Q may destroyed once they have been successfully deposited in remote locations. Remote locations124may include any suitable sever, storage, or other system for storing data or information.

In another example, secrets112,116, and those not shown may be stored locally. These may be stored in an encrypted manner. For example, secrets112may be stored locally in system100. Each of secrets112A-112P may have an individual instance of a public key120A-120P associated with it. There may be a corresponding private key for each public key, as discussed further below. Using asymmetric encryption circuit118, public keys120may be used to create encrypted copies122of respective secrets112. Asymmetric encryption circuit118may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices. Respective ones of secrets112may be destroyed once respective ones of encrypted copies122have been created.

FIG. 2is an illustration of a process for recovering or reconstituting a distributed secret for a security credential, according to embodiments of the present disclosure. The security credential may have been securely destroyed. Illustrated inFIG. 2for recovering or reconstituting a distributed secret for a security credential is a threshold decryption system130. System130may be implemented within system100, or implemented in a manner that is communicatively coupled and will work with system100. Threshold decryption system130may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices.

First, any encrypted copies of secrets that were created as shown inFIG. 1may be restored. As discussed above, it was shown that N shards were created. Then, secrets were created for each shard. The number of secrets created for each shard depended upon the threshold encryption used. A set of quantity P secrets was created by threshold encryption P≥TPfunction circuit110and a set of quantity Q secrets was created by threshold encryption function Q≥TQcircuit114. Since creation of secrets was done, for example, using threshold encryption (P≥TP, Q≥TQ), only a subset T (which may vary from function to function, such as TPor TQ) of the original quantity of secrets are needed to recreate the shard. For example, inFIG. 1, shard 1108A was split by threshold encryption P≥TPfunction circuit110into a set of P external secrets112. Even though a total number of P secrets of secrets112were generated, only a total number of TPsecrets of secrets112are required to regenerate shard 1108A. Similarly, a total number of Q secrets of secrets116were generated from shard N108N, and only a total number of TPsecrets of secrets116are required to regenerate shard N108N. Since in threshold encryption circuit104, N=TN, all shards 1 through N are required to reconstitute security credential102.

Encrypted external secret stored locally122A was generated using asymmetric encryption circuit118A and public key120A on secret112A. To restore the locally encrypted secrets, for example, an external secret stored locally132A may be decrypted off-site. Secret132A may be sent to an external asymmetric decryption circuit134A from threshold decryption system130.

At external asymmetric decryption circuit134A, using private key136A, external secret138A may be decrypted and sent back to threshold decryption system130. Decryption circuit134A may use the same algorithm as was used in the asymmetric encryption (such as encryption circuit118A) used to create secret132A. Secret138A may be the reconstitution of one of secrets112, such as secret112A. Similarly, encrypted external secret stored locally132T may be sent to an external asymmetric decryption circuit134T from threshold decryption system130. Here, using private key136T, secret138T may be decrypted and sent back to threshold decryption system130. Secret138T may be the reconstitution of one of secrets112, such as secret112P. Moreover, additional intervening encrypted external secrets stored locally132(not shown) may be reconstituted using respective asymmetric decryption circuits134(not shown) using respective private keys136(not shown). There may be TPsecrets138to reconstitute the original shard using threshold decryption function P≥TPcircuit142. If threshold decryption function P≥TPcircuit142reconstitutes secrets generated by function threshold encryption function P≥T function circuit110, then threshold decryption function P≥TPcircuit142may use a threshold of TPsecrets138. Again, TPmay be less than P, the total number of secrets derived from the original shard.P

Because the set of TPsecrets138that are reconstituted from encrypted external secrets stored locally132may be smaller or equal than the number of P secrets112that were originally generated, secret138A might not necessarily correspond, specifically, to secret112A, and vice-versa; encrypted external secret stored locally122A might not necessarily correspond, specifically, to encrypted external secret stored locally132A, and vice-versa; asymmetric decryption circuit134A might not necessarily correspond, specifically, to asymmetric encryption circuit118A, and vice-versa; public key120A might not necessarily correspond, specifically, to private key136A, and vice-versa. However, each of secrets112will correspond to one or more of secrets138; each of asymmetric encryption circuit118will correspond to one or more of asymmetric decryption circuit134; each of encrypted external secrets stored locally122will correspond to one or more of encrypted external secrets stored locally132; each of private keys136will correspond to one or more of public keys120; each of secrets138will correspond to one or more of secrets112; each of asymmetric decryption circuit134will correspond to one or more of asymmetric encryption circuit118; each of encrypted external secrets stored locally132will correspond to one or more of encrypted external secrets stored locally122; and each of public keys120will correspond to one or more of private keys136. The “one or more” correspondence between the elements ofFIGS. 1 and 2depends upon whether any keys or encryption/decryption routines are reused for multiple secrets.

Next, using secrets138A-138T (which are a subset of a total number of secrets138A-138P), a shard 1146A can be reconstituted using threshold decryption P≥TPfunction circuit142. Shard 1146A may correspond to shard 1108A inFIG. 1. Once shard 1146ahas been created, secrets138A-138T used to reconstitute may be securely destroyed.

Other secrets that have been remotely stored may be retrieved from various external locations138where they are stored. Note only T locations might need to return secrets, wherein T corresponds to the threshold of the function used to generate the secrets stored in external locations. Therefore, remote locations138A-138T may supply secrets140A-140T to threshold decryption system130. These may be provided through a secure or encrypted communications channel. Using secrets140, the original shard N146N can be reconstituted using threshold decryption function Q≥TQcircuit144. Once shard N146N has been created, all secrets140used to reconstitute may be securely destroyed. There may be TQsecrets140to reconstitute the original shard using threshold decryption function Q≥TQcircuit144. If threshold decryption function Q≥TQcircuit144reconstitutes secrets generated by function threshold encryption function Q≥TQcircuit114, then threshold decryption function Q≥TQcircuit144may use a threshold of TQsecrets140.

Because only a subset of secrets (such as quantity TQ) is needed to reconstitute the shard, only a subset of remote locations138(quantity TQ) need to yield the remotely stored secrets. Accordingly, remote locations124may correspond to various ones of remote locations138, though not necessarily in a 1:1 manner. Each of remote locations124may correspond to one or more of remote locations138, and vice-versa. Each of secrets140may correspond to one or more of secrets116, and vice-versa.

Although generation of shard 1146A through use of locally stored secrets132and shard N146N through use of remotely stored secrets140are shown, generation of shards146may be performed through any suitable combination of locally or remote stored secrets. These are provided as a mere example. Generation of other shards146are not shown inFIG. 2but may be performed in any suitable manner. N shards146may be reconstituted, corresponding to shards108.

Shards146may be used by threshold decryption N=TNfunction circuit148to reconstitute a security credential149. Security credential149, if correctly reconstituted, may be the same as security credential102. All of the N shards108that were created inFIG. 1by threshold encryption function circuit104may be presented to threshold decryption N=TNfunction circuit148to successfully reconstitute security credential149. Once security credential149has been created, shards146may be securely destroyed.

It can be seen from the examples above that there are different methods to distribute the secrets. Although locally encrypted versions and remote storage were used, any other suitable methods may be employed. In one embodiment, the type of distribution may be common to a given shard. For example, secrets112derived from shard 1108A may be encrypted and stored locally, while secrets116derived from shard N108N may be stored remotely. As such a given shard and its associated secrets can be grouped in a “zone.” The shard for each zone can be named the zone shard for that particular zone.

Circuits134,142,144,148may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices.

FIG. 3is an illustration of systems for generating and recovering a distributed secret for a security credential, according to embodiments of the present disclosure.FIG. 3illustrates two distribution mechanisms. One such distribution may be performed with public key infrastructure (PKI), and another such distribution may be to distribute the secrets to multiple servers. The multiple servers may be in remote storage locations. Shown inFIG. 3are two zones, one for each of the example distribution mechanisms. Although there are only two zones shown for the sake of clarity, there is no limit to the number, type, and combination of zones that can be implemented.

Illustrated inFIG. 3are two example servers150. Each of servers150may be implemented in any suitable manner, such as by a blade server, computer, stand-alone machine, virtual machine, or any other suitable electronic device. Servers150may each implement, fully or in part, system100fromFIG. 1and system120fromFIG. 2. Two servers, server 1150A and server 2150B are shown, though any suitable number and kind of servers may be used.

A set of zone shards may be generated for a given security credential. As a result, multiple shards and multiple secrets derived from each shard may be tied to the original security credential.

Each server150may include any suitable number and kind of security credentials170. Security credentials170may be used to create shards by zone shard generation function circuit176. Zone shard generation function circuit176may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices. Zone shard generation function circuit176may implement, fully or in part, system100fromFIG. 1and system120fromFIG. 2. Zone shard generation function circuit176may be configured to generate shards into zones, according to how secrets will be derived from the shard and stored.

For a given security credential from security credentials170, zone shard generation function circuit176may be configured to generate a zone 1 shard172and a zone 2 shard178. These may be created using threshold encryption N=TNfunction circuit104. Next, secrets from the respective shards may be created and distributed. Once all zone shards have been generated, security credential170may be completely and securely destroyed.

Zone 1 shard172may be processed by an external secret generation function circuit166to create multiple secrets158,162. Although only 2 secrets158,162are shown for clarity, any suitable number of secrets may be generated using a threshold encryption X≥T function, such as function circuits110,114. Zone 1 shard172may be securely destroyed once secrets158,162have been created. Public and private keys may be created through any suitable process. Public keys152B,154B may be stored on servers150. Public key152B may be used by a PKI function circuit156to create an encrypted secret164from secret158. In server 1150A, this may refer to generating encrypted secret 1-1164A from secret 1-1158A. This may be performed by PKI function circuit156A using public key152B. In server 2150B, this may refer to generating encrypted secret 2-1164B from secret 2-1158B. This may be performed by PKI function circuit156B using public key152B. Notably, the same public key—public key152B—may be used by both server 1150A and server 2150B to encrypt secrets158therein to create encrypted secrets164. Once encrypted secret164has been created, secret158may be securely destroyed. Encrypted secret164may be stored locally.

Similarly, public key154B may be used by a PKI function circuit160to create an encrypted secret 2168from secret 2162. Once encrypted secret 2168has been created, secret 2162may be destroyed. In server 1150A, this may refer to generating encrypted secret 1-2168A from secret 1-2162A, performed by PKI function circuit160A using public key154B. In server 2150B, this may refer to generating encrypted secret 2-2168B from secret 2-2162B, performed by PKI function circuit160B using public key154B. Again, the same public key—public key154B—may be used by both server 1150A and server 2150B to encrypt secrets162therein to create encrypted secrets168.

PKI function circuits156,160may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices.

Zone 2 shard178may be processed by an external secret generation function circuit182. External secret generation function circuit182may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices. External secret generation function circuit182may be an implementation of function circuit114. External secret generation function circuit182may be configured to generate multiple secrets, such as secret 3184and secret 4180. Although generation of only two such secrets is shown for clarity, multiple secrets can be generated using a threshold encryption X≥TXfunction such as function circuits110,114. Zone 2 shard178may be securely deleted once secret 3184and secret 4180have been created.

Secret 3184and secret 4180may be securely transmitted to remote storage locations. In one embodiment, secret 3184and secret 4180may be transmitted and stored on different remote storage locations. For example, secret 1-4180A may be securely transmitted and stored on remote storage location 1190, at location186A. Secret 1-3184A may be securely transmitted and stored on remote storage location 2192, at location188A. Once securely stored, secret 3184and secret 4180may be securely destroyed.

Servers150may reconstitute security credentials through use of keys to first reconstitute the zone shards. At least two external keys may be required to reconstitute zone shards172,178inFIG. 3. However, any number of keys might be required to reconstitute a given shard, depending upon the encryption scheme.

Servers150may reconstitute zone 1 shard172. Encrypted secret164may be securely transmitted to an external PKI function circuit151. Private key152A may be used by external PKI function circuit151to create secret158from encrypted secret164. External PKI function circuit151may securely transmit secret158back to server150. External PKI function circuit151might require a decryption algorithm corresponding to the encryption function used on server150. For example, external PKI function circuit151may perform decryption corresponding to the encryption that was performed by PKI function circuit156. Similarly, encrypted secret168may be securely transmitted to external PKI function circuit153. Private key154A may be used by external PKI function circuit153to create secret162from encrypted secret168and securely transmit it back to server150. External PKI function circuit153might require a decryption algorithm corresponding to the encryption function used on server150. For example, external PKI function circuit153may perform decryption corresponding to the encryption that was performed by PKI function circuit160. Function circuits151,153may be implemented in any suitable manner, such as by instructions in the medium for execution by the processor, a function, library call, subroutine, shared library, software as a service, analog circuitry, digital circuitry, control logic, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices.

Servers150may reconstitute zone shard 2178. Server150may retrieve secret 4186from remote storage location 1190, and may store it locally. Secret 3188may be retrieved from remote storage location 2192and stored locally. Local secret 4180and local secret 3184may be used together by external secret generation function circuit182to generate zone 2 shard178. Local secret 4180and local secret 3184may be securely destroyed once zone 2 shard178has been created.

Servers150may then reconstitute the original security credential170. Zone 1 shard172and zone 2 shard178may be used together by zone shard generation function circuit176to reconstitute a corresponding security credential170. Once security credential170has been created, zone 1 shard172and zone 2 shard178may be securely destroyed.

InFIG. 3, it can be seen that there are two zone class types. In one zone the secrets are stored externally to server150. In the second zone, the external secrets are stored locally in an encrypted state in sever150. In the second zone, the same public keys152B,154B may be each used on each server150A,150B to encrypt secrets. Consequently, private keys152A,154A can be used to decrypt secrets for either server150A,150B. Therefore, in this example, the private key is independent of the server and tied to the owner of that key. However, both private keys152A,154A may be required to regenerate zone 1 shard172and, consequently, a security credential170. A zone with this property may be referenced as a device-independent zone or server-independent zone.

However, secrets 1-4186A and 2-4186B on remote storage location 1190and secrets 1-3188A and 2-3188B on remote storage location 2192must be provided to their respective server,150A,150B. Secret 2-4186B from remote storage location 1190cannot be used on server150A. Moreover, secret 2-3188B from remote storage location 2192cannot be used on Server150A. Thus, a zone with this property may be referenced as a device-dependent zone or server-dependent zone.

Thus, in one embodiment, successful reconstitution of security credentials requires one or more server-independent keys and one or more server-dependent secrets to be provided to reconstitute the security credential. The server-independent keys can be realized as physical devices, such as a hardware dongle, smart card, or mobile device app. Thus, a remote credential (a server-independent physical device, for example) and a local credential (a server-dependent credential stored on the remotely located server, for example) may be required to reconstitute the security credentials. This may significantly improve the security of the system when compared to simply storing security credentials170themselves. Although server-dependent and server-independent external keys are shown in different zones, it is possible to mix both in the same zone. Doing so may alter the security level of the solution.

Server-independent secrets may allow the owner of the private key to decrypt a locally stored encrypted secret on a server that used the corresponding public key to encrypt it. For example, inFIG. 3, owners of private keys152A,154A can successfully recreate zone 1 shard on either server150A,150B. However, such owners could not regenerate security credential170A or security credential170B unless the corresponding zone 2 shard is also recreated. Zone 2 shard recreation may require server-dependent authorization. An example of how this may be used is as follows. A server150may be hosted in a location not operated by the owner of server150. Private/public key pairs may be realized as a smart card for the private keys. One smart card may be presented to the server owner and a different smart card presented to the location manager. The public keys are used on each server to create locally stored encrypted secrets. These servers150may require the local application of the smart card of the owner and that of the location manager to decrypt them. Further, server-dependent secrets are created by the server owner system administrator and also by the location system administrator. These secrets are stored externally. To reconstitute security credential170, the system administrators must restore the zone 2 shard on a specific server150. The smart card users can then restore the zone 1 shard on that same server150. Neither the owners of the smart cards, who must be physically present to use them, or the system administrators working remotely, can reconstitute a security credential on their own. Additionally, the smart card owners need only carry one smart card to participate in the process since that card can decrypt secrets on any server that used corresponding public key to encrypt the secrets. The system prevents remote reconstitution of security credentials without the participation of a local smart card holder. That is, no unattended access is allowed. Similarly, local smart card users cannot reconstitute a security credential without the participation of the system administrators. That is, no unsupervised access might be allowed.

FIG. 4represents a specific embodiment of the implementation of a smart card solution using Near Field Communications (NFC).

A server240can be implemented using two independent processing systems. Server240may be an implementation of server150. A baseboard motherboard controller (BMC)200may provide standard BMC functions, such as a server management interface. BMC200may be a standalone system and may include a processor210, embedded operating system202, random access memory (RAM)204, and wireless interface222. Wireless interface222may be implemented by analog circuitry, digital circuitry, control logic, instructions for execution by a processor, digital logic circuits programmed through hardware description language, ASIC, FPGA, PLD, or any suitable combination thereof, or any other suitable mechanism, whether in a unitary device or spread over several devices. Wireless interface222may be configured to provide a near field network, using NFC, to communicate with an NFC-enabled smart card226. Motherboard230may provide the main processing for server240using a System-on-A-Chip (SoC)234, I/O expanders238, and UEFI and firmware236. BMC200may communicate to UEFI and firmware236via a serial control interface218and I/O expanders238.

BMC processor210may have its own AES/RSA encryption function circuit216to provide cryptographic functions independently of motherboard230. Using AES/RSA encryption function circuit216, together with internal read-only memory (ROM)214and internal RAM212, processor210may provide asymmetric encryption, or PKI, functions. Consequently, processor210can, for example, implement PKI function circuits156,160for each server150. Processor210may store public keys152B,154B locally. Processor210may create and store encrypted secrets164,168. BMC200, using processor210and wireless interface222can then securely transmit a copy of encrypted secrets164,168to the NFC-enabled smart card226using near field network224. NFC-enabled smart card226may contain a private key152and decrypt encrypted secret164,168transmit it back to BMC200via near field network224. Secret158,162can then be used to compute zone 1 shard172. Processor210can also provide external secret generation166function circuit to create secrets158,162from the zone 1 shard172. Conversely, processor210can also provide external secret generation function circuit166to reconstitute zone 1 shard172from secrets158,162reconstituted using NFC-enabled Smart Card226.

Using the above embodiment provides two distinct advantages. First, the owner of the public key must be physically close—within a few inches—of wireless interface222, providing a physical layer of security. Second, generation of secrets158,162and creation and storage of encrypted secrets164,168are isolated from motherboard SoC234. Motherboard SoC234can be used to process the server-dependent secrets and BMC200can process the server-independent secrets. This isolation may further prevent a remote administrator from accessing server-independent secrets, or a local smart card owner from access server-dependent secrets, thus preventing unattended and unsupervised access.

FIG. 5is an illustration of an example method500for security credential destruction and reconstitution, according to embodiments of the present disclosure. Method500may be performed by any suitable mechanism, such as by the systems, components, servers, or functions ofFIGS. 1-4. Method500may begin at any suitable step. Steps of method500may be performed in any suitable order, repeated, rearranged, performed recursively, omitted, or performed in parallel.

At505, a system and servers may boot up. Security credentials may be used and stored.

At510, it may be determined whether any of the security credentials are to be securely deleted. If so, method500may proceed to515. Otherwise, method500may proceed to540.

At515, N=TNthreshold encryption may be performed to generate N shards from the security credential. At least one of the shards may be stored locally or in a device independent manner, and at least one of the shards may be stored remotely or in a device dependent manner. The security credential may be securely deleted from the server.

At520, a given shard may be considered. If the shard is to be stored locally or in a device independent manner, method500may proceed to525. If the shard is to be stored remotely or in a device dependent manner, method500may proceed to530.

At525, P≥TPthreshold encryption may be performed to generate P secrets from the shard. Each secret may be encrypted with, for example, public keys. Each encrypted secret may be stored locally. The shard and unencrypted secrets may be securely deleted. Method500may proceed to535.

At530, Q≥TQthreshold encryption may be performed to generate Q secrets from the shard. Each secret may be encrypted as part of secure transmission to a remote location. Each securely transmitted secret may be stored remotely. Different secrets may be stored in different remote locations. The shard and local unencrypted copies of the secrets may be securely deleted. Method500may proceed to535.

At535, it may be determined whether additional shards are to be processed. If so, method500may return to520. Otherwise, method500may return to510.

At540, it may be determined whether any of the security credentials previously deleted are to be reconstituted. If so, method500may proceed to545. Otherwise, method500may return to510.

At545, it may be determined whether secrets for a given shard of the security credential were stored remotely or in a device dependent manner, or whether the secrets for the given shard were stored locally or in a device independent manner. If the secrets were stored locally or in a device independent manner, method500may proceed to550. If the secrets were stored remotely or in a device dependent manner, method500may proceed to555.

At550, remote processing may be accessed for private key decryption of the locally stored encrypted secrets. A sufficient number of secrets, albeit a subset of the total secrets generated by the shard, may be returned. The shard may be reconstituted, and the secrets deleted. Method500may proceed to560.

At555, remotely stored secrets may be retrieved. A sufficient number of secrets, albeit a subset of the total secrets generated by the shard, may be returned. The shard may be reconstituted, and the secrets deleted. Method500may proceed to560.

At560, it may be determined whether there are additional shards to be reconstituted. If so, method500may return to545. Otherwise, method500may proceed to565.

At565, the original security credential may be reconstituted from the TNrecovered shards. The shards may be deleted. Method500may return to510.

Although example embodiments have been described above, other variations and embodiments may be made from this disclosure without departing from the spirit and scope of these embodiments.