Abstract: A database server receives a data request from a client. In response to the data request, the database server selects, from a database, actual data that satisfies criteria specified by the data request. The database server retrieves the selected actual data from the database. Also in response to the data request, the database server redacts the retrieved data in real time without modifying the actual data contained within the database. This may be accomplished by the prior insertion of masking operators into a top SELECT clause of a query representation generated during semantic analysis. The database server returns the redacted data to the client as a reply to the data request.

Abstract: One embodiment of the present invention provides a system for performing selective encryption/decryption in a data storage system. During operation, the system receives a data block from a storage medium at an input/output layer, wherein the input/output layer serves as an interface between the storage medium and a buffer cache. Next, the system determines whether the data block is an encrypted data block. If not, the system stores the data block in the buffer cache. Otherwise, if the data block is an encrypted data block, the system retrieves a storage-key, wherein the storage-key is associated with a subset of storage, which is associated with the encrypted data block. Using the storage-key, the system then decrypts the encrypted data block to produce a decrypted data block. Finally, the system stores the decrypted data block in the buffer cache, wherein the data block remains encrypted in the storage medium.

Abstract: A database server receives a data request from a client. In response to the data request, the database server selects, from a database, actual data that satisfies criteria specified by the data request. The database server retrieves the selected actual data from the database. Also in response to the data request, the database server redacts the retrieved data in real time without modifying the actual data contained within the database. This may be accomplished by the prior insertion of masking operators into a top SELECT clause of a query representation generated during semantic analysis. The database server returns the redacted data to the client as a reply to the data request.

Abstract: Embodiments of the present disclosure provide a system that performs non-deterministic auditing. The system audits an operation, a record associated with which is maintained in an audit log. In one embodiment, the system subsequently determines whether the operation satisfies one or more criteria. In response to the operation satisfying the criteria, the system protects the audit log. In a further embodiment, the system protects the audit log based on a probability distribution, which indicates a frequency of audit log protection.

Abstract: A database server receives a data request from a client. In response to the data request, the database server selects, from a database, actual data that satisfies criteria specified by the data request. The database server retrieves the selected actual data from the database. Also in response to the data request, the database server redacts the retrieved data in real time without modifying the actual data contained within the database. This may be accomplished by the prior insertion of masking operators into a top SELECT clause of a query representation generated during semantic analysis. The database server returns the redacted data to the client as a reply to the data request.

Abstract: One embodiment of the present invention provides a system that facilitates encrypting data. During operation, the system receives unencrypted data to be encrypted. Next, the system preprocesses the unencrypted data to create preprocessed unencrypted data, wherein preprocessing the unencrypted data involves generating a salt (wherein the salt facilitates in determining if the subsequently encrypted data has been altered) and concatenating the salt and the unencrypted data to create the preprocessed unencrypted data. Next, the system encrypts the preprocessed unencrypted data to create the encrypted data. Because the salt has already been applied to the plaintext data, it does not need to be reapplied during the encryption phase as is typically done in encryption. Finally, the system stores a copy of the salt with the encrypted data.

Abstract: A database server receives a data request from a client. In response to the data request, the database server selects, from a database, actual data that satisfies criteria specified by the data request. The database server retrieves the selected actual data from the database. Also in response to the data request, the database server redacts the retrieved data in real time without modifying the actual data contained within the database. This may be accomplished by the prior insertion of masking operators into a top SELECT clause of a query representation generated during semantic analysis. The database server returns the redacted data to the client as a reply to the data request.

Abstract: A method and apparatus is provided for generating a masked value from a cryptographically transformed value by using the cryptographically transformed value as a random seed, without decrypting the cryptographically transformed value. A query is evaluated against a set of data to produce a result. The result may be cryptographically transformed or unencrypted. If the result is unencrypted, the result may be cryptographically transformed to produce a random seed. If the result is already cryptographically transformed, then the result is used as the random seed. The random seed is used to generate a masked value, without decrypting the cryptographically transformed random seed value. The masked value conforms to a particular data characteristic such as a data format or a data type, which may be determined from metadata stored in a database, received with a query, or gleaned from unencrypted data. The masked value is returned as a result of the query.

Abstract: One embodiment of the present invention provides a system that re-establishes communication between a client and a server after an unexpected termination of communication. During operation, the system receives a request from the client at the server to re-establish communication between the client and the server, wherein the request includes a temporary credential. If the temporary credential is valid, the system temporarily re-establishes communication between the client and the server, until the client can be re-authenticated with a permanent credential.

Abstract: One embodiment of the present invention provides a system that facilitates generating random data-encryption keys for data files. During operation, the system receives a command at a computer system to create a data file that may include encrypted data. This data file includes a wrapped data-encryption key to facilitate encrypting and decrypting data. In response to the command, the system generates a bit pattern to be used as the wrapped data-encryption key. Finally, the system creates the data file, which includes the bit pattern as the wrapped data-encryption key.

Abstract: Embodiments of the present disclosure provide a system that performs non-deterministic auditing. The system audits an operation, a record associated with which is maintained in an audit log. In one embodiment, the system subsequently determines whether the operation satisfies one or more criteria. In response to the operation satisfying the criteria, the system protects the audit log. In a further embodiment, the system protects the audit log based on a probability distribution, which indicates a frequency of audit log protection.

Abstract: One embodiment of the present invention provides a system that facilitates role-based cryptographic key management. The system operates by receiving a request at a database server from a user to perform a cryptographic operation on data on the database server, wherein the user is a member of a role, and wherein the role has been granted permission to perform the cryptographic operation on the data. Next, the system receives from the user at the database server a user key, which is associated with the user. The system then unwraps a wrapped role key with the user key to obtain a role key, which is associated with the role. Next, the system unwraps a wrapped data key with the role key to obtain a data key, which is used to encrypt and decrypt the data. Finally, the system uses the data key to perform the cryptographic operation on the data.

Abstract: A method and apparatus is provided for generating a masked value from a cryptographically transformed value by using the cryptographically transformed value as a random seed, without decrypting the cryptographically transformed value. A query is evaluated against a set of data to produce a result. The result may be cryptographically transformed or unencrypted. If the result is unencrypted, the result may be cryptographically transformed to produce a random seed. If the result is already cryptographically transformed, then the result is used as the random seed. The random seed is used to generate a masked value, without decrypting the cryptographically transformed random seed value. The masked value conforms to a particular data characteristic such as a data format or a data type, which may be determined from metadata stored in a database, received with a query, or gleaned from unencrypted data. The masked value is returned as a result of the query.

Abstract: One embodiment of the present invention provides a system for managing keys. During operation, the system authenticates a client at a key manager. Next, the system receives a token from the client at the key manager, wherein the token is associated with a customer key, and includes a token authenticator. This token authenticator comprises one-half of an authenticator pair which is used to determine if the client is the owner of the customer key. Next, the system decrypts the token using a master key. The system then verifies a client authenticator, which comprises the other half of the authenticator pair which is used to determine if the client is the owner of the customer key. If the client is the owner of the customer key, the system sends the customer key to the client, which enables the client to encrypt/decrypt data. Finally, the client deletes the customer key.

Abstract: One embodiment of the present invention provides a system that authorizes a sensitive database operation. During operation, the system receives a request to perform a sensitive database operation. Note that, a sensitive database operation is an operation which, in the hands of a malicious user, poses a serious security threat. Next, the system determines a multiparty authorization requirement for the sensitive database operation, wherein the multiparty authorization requirement specifies a set of approvals required for authorizing the sensitive database operation. The system then sends approval requests to one or more approving parties based on the multiparty authorization requirement. Next, the system receives approvals for authorizing the sensitive database operation. The system then determines whether the approvals satisfy the multiparty authorization requirement.

Abstract: One embodiment of the present invention provides a system for managing keys. During operation, the system receives a request from a user at a database to encrypt/decrypt data at the database. In response to this request, the system sends a user-token to the user, wherein the user-token includes a user-key encrypted with a user-secret thereby enabling the user to decrypt the user-key with the user-secret. Next, the system receives the decrypted user-key from the user. The system then uses the user-key to encrypt/decrypt the data at the database. Finally, the system deletes the user-key at the database.

Abstract: One embodiment of the present invention provides a system that enables a background process to access encrypted data. During operation, the system executes the background process. Next, the system obtains a set of unencrypted keys by decrypting a set of encrypted keys with a server-key. The system then makes the set of unencrypted keys available to the background process, thereby enabling the background process to encrypt and decrypt data. Finally, the system deletes the set of unencrypted keys.

Abstract: One embodiment of the present invention provides a system that facilitates generating random data-encryption keys for data files. During operation, the system receives a command at a computer system to create a data file that may include encrypted data. This data file includes a wrapped data-encryption key to facilitate encrypting and decrypting data. In response to the command, the system generates a bit pattern to be used as the wrapped data-encryption key. Finally, the system creates the data file, which includes the bit pattern as the wrapped data-encryption key.

Abstract: One embodiment of the present invention provides a system that facilitates encrypting data. During operation, the system receives unencrypted data to be encrypted. Next, the system preprocesses the unencrypted data to create preprocessed unencrypted data, wherein preprocessing the unencrypted data involves generating a salt (wherein the salt facilitates in determining if the subsequently encrypted data has been altered) and concatenating the salt and the unencrypted data to create the preprocessed unencrypted data. Next, the system encrypts the preprocessed unencrypted data to create the encrypted data. Because the salt has already been applied to the plaintext data, it does not need to be reapplied during the encryption phase as is typically done in encryption. Finally, the system stores a copy of the salt with the encrypted data.

Abstract: One embodiment of the present invention provides a system that facilitates using an external security device to secure data in a database without having to modify database applications. The system operates by receiving a request at the database to perform an encryption/decryption operation, wherein the encryption/decryption operation is performed with the assistance of the external security module in a manner that is transparent to database applications. In response to the request, the system passes a wrapped (encrypted) column key (a key used to encrypt data within the database) to an external security module, wherein the wrapped column key is a column key encrypted with a master key that exists only within the external security module. The system then unwraps (decrypts) the wrapped column key in the external security module to retrieve the column key. Next, the system returns the column key to the database.