Abstract: Format-preserving encryption and decryption processes are provided. The encryption and decryption processes may use a block cipher. A string that is to be encrypted or decrypted may be converted to a unique binary value. The block cipher may operate on the binary value. If the output of the block cipher that is produced is not representative of a string that is in the same format as the original string, the block cipher may be applied again. The block cipher may be repeatedly applied in this way during format-preserving encryption operations and during format-preserving decryption operations until a format-compliant output is produced. Selective access may be provided to portions of a string that have been encrypted using format-preserving encryption.

Abstract: A token generating organization may include distributed tokenization systems for generating tokens corresponding to sensitive information. Sensitive information may include sensitive numbers such as social security numbers, credit card numbers or other private numbers. A tokenization system may include multiple physically distinct hardware platforms each having a tokenization server and a database. A tokenization server may run portions of a sensitive number through a predetermined number of rounds of a Feistel network. Each round of the Feistel network may include tokenizing portions of the sensitive number using a fractional token table stored an associated database and modifying the tokenized portions by reversibly adding portions of the sensitive number to the tokenized portions. The fractional token table may include partial sensitive numbers and corresponding partial tokens.

Abstract: Online ordering systems allow a user to submit sensitive information such as payment card information to a merchant in encrypted form. A payment card processor server may be used to provide the user's web browser with code for an encryption function, a cryptographic key, and a key identifier. The web browser may encrypt the payment card information by executing the encryption function and using the key. The encrypted payment card information may be supplied to the merchant over the internet. A key identifier that identifies which cryptographic key was used in encrypting the payment card information may be provided to the merchant without providing the merchant with access to the key. The merchant can forward the encrypted payment card information to the credit card processor server with the key identifier. The processor server can use the key identifier to obtain the key and decrypt the payment card information for authorization.

Abstract: Techniques for using padding in format preserving encryption are provided. In one aspect, it may be determined if padding of a plaintext undergoing format preserving encryption is needed. A pseudo random padding length may be calculated when it is determined that padding is needed. The calculated length of padding may be added to the plaintext when it is determined that padding is needed. The plaintext and added padding may be encrypted using format preserving encryption to create a cipher text.

Abstract: Examples disclosed herein relate to encryption of community-based security information. Some examples may enable authorizing a user of a community to access an encrypted data item (e.g., at least an encrypted portion of community-based security information of that community) using a decryption key. The community may be generated on a security information sharing platform based on a set of community attributes. The decryption key may comprise a private key corresponding to each user attribute of a set of user attributes that are associated with the authorized user where the set of user attributes satisfy the set of community attributes.

Abstract: Examples disclosed herein relate to generating communities on a security information sharing platform. Some examples may enable identifying a set of community attributes to be used to generate a community on the security information sharing platform that enables sharing of security information among a plurality of communities. Some examples may enable authorizing a first user to access community-based security information of the community where the first user is associated a set of user attributes that satisfy the set of community attributes. A security indicator may be obtained from the first user of the community. Information related to the security indicator may be obtained from a second user of the community. Some examples may enable including the security indicator and the information related to the security indicator in the community-based security information of the community.

Abstract: Examples discussed herein disclose, among other things, an encrypting device. The encrypting device may include a key engine to obtain a first key associated with a first access level, and a second key associated with a second access level. The encrypting device may also include a multi-key encryption engine to encrypt a first portion of the plaintext with the first key, and encrypt a second portion of the plaintext with the second key, where the first portion may include more detailed information than the second portion, and where the first access level may be higher than the second access level.

Abstract: Systems and methods are provided for securing payment card information. A user may present a payment card such as a credit card to point-of-sale equipment. The point-of-sale equipment may encrypt the payment card information. An encryption algorithm may be used that takes as inputs a first part of the payment card information, a tweak formed by a second part of the payment card information, and an encryption key. The encrypted payment card information may be conveyed to a gateway over a communications network. The gateway may identify which encryption algorithm was used in encrypting the payment card information and may re-encrypt the payment card information using a format preserving encryption algorithm. A network-based service may be used to remotely perform functions for the gateway.

Abstract: A computing device includes a processor and a machine-readable storage medium storing instructions. The instructions are executable by the processor to: initiate a transition mode in a database comprising a plurality of data elements; and responsive to a first query for a first data element during the transition mode, determine whether the first data element is already encrypted in the database. The instructions are further executable to, responsive to a determination that the first data element is already encrypted in the database: decrypt the first data element, and return the decrypted first data element to the first query. The instructions are further executable to, responsive to a determination that the first data element is not already encrypted in the database: return the first data element to the first query without decryption, and encrypt the first data element in the database.

Abstract: A technique includes performing element-by-element encryption of a segment of the plaintext string to provide a segment of an encrypted string. Performing the element-by-element encryption includes, for a given string element of the segment of the plaintext string, encrypting the given string element to provide a given string element of the segment of the encrypted string; and tweaking the encryption of the given string element based on a selector that includes multiple string elements of the encrypted string. The technique may include searching an encrypted database based on the encrypted string.

Abstract: In some examples, a system receives, from a sender, an access control value generated based on information of a plurality of recipients. The system sends, to the sender, a signed version of the access control value for sending by the sender to the plurality of recipients with an encrypted message. The system receives, from a first recipient a request for a key to decrypt the encrypted message, a signed access control value and recipient information for deriving the access control value. The system determines whether the first recipient is one of the plurality of recipients using the signed access control value and the recipient information.

Abstract: A data processing system is provided that includes applications, databases, encryption engines, and decryption engines. Encryption and decryption engines may be used to perform format-preserving encryption on data strings stored in a database. Applications may be used to embed information in data strings. Information may be embedded by using a character set that is larger than a character set being used by a data string. A data string may be converted into a larger character set, analogous to converting a number from a lower base to higher base. Such a conversion may shorten a data string, allowing information to be embedded as appended characters.

Abstract: Example implementations relate to a security information sharing platform that enables sharing of security information among a plurality of members. For example, in an implementation, a system may determine that a first member of a community of a security information sharing platform is entitled access to a first set of encrypted information shared by a second member of the community. The system may also receive a request, from the first member, to access the first set of encrypted information, the request including a masked parameter. The system may also determine that the masked parameter matches an access parameter for accessing the first set of encrypted information and provide the first member access to the first set of encrypted information in response to determining that the masked parameter matches the access parameter.

Abstract: A customer may provide a merchant with primary account number information in connection with a purchase transaction. The merchant may send an associated authorization request to a payment card processor. A tokenization server at the payment card processor may generate a token corresponding to the primary account number. To secure the token, the token may be encrypted at the payment card processor using a cryptographic key shared with the merchant. A structure preserving encryption algorithm may be used in encrypting the token. A processor identifier may be embedded in the encrypted version of the token during the structure preserving encryption operation. The merchant can use the shared key to decrypt the token and extract the processor identifier. A settlement request may be directed to the processor from the merchant to settle the transaction using the processor identifier.

Abstract: Examples discussed herein disclose, among other things, an encrypting device. The encrypting device may include a key engine to obtain a first key associated with a first access level, and a second key associated with a second access level. The encrypting device may also include a multi-key encryption engine to encrypt a first portion of the plaintext with the first key, and encrypt a second portion of the plaintext with the second key, where the first portion may include more detailed information than the second portion, and where the first access level may be higher than the second access level.

Abstract: A technique includes performing element-by-element encryption of a segment of the plaintext string to provide a segment of an encrypted string. Performing the element-by-element encryption includes, for a given string element of the segment of the plaintext string, encrypting the given string element to provide a given string element of the segment of the encrypted string; and tweaking the encryption of the given string element based on a selector that includes multiple string elements of the encrypted string. The technique may include searching an encrypted database based on the encrypted string.

Abstract: Examples disclosed herein relate to encryption of community-based security information. Some examples may enable authorizing a user of a community to access an encrypted data item (e.g., at least an encrypted portion of community-based security information of that community) using a decryption key. The community may be generated on a security information sharing platform based on a set of community attributes. The decryption key may comprise a private key corresponding to each user attribute of a set of user attributes that are associated with the authorized user where the set of user attributes satisfy the set of community attributes.

Abstract: Examples disclosed herein relate to generating communities on a security information sharing platform. Some examples may enable identifying a set of community attributes to be used to generate a community on the security information sharing platform that enables sharing of security information among a plurality of communities. Some examples may enable authorizing a first user to access community-based security information of the community where the first user is associated a set of user attributes that satisfy the set of community attributes. A security indicator may be obtained from the first user of the community. Information related to the security indicator may be obtained from a second user of the community. Some examples may enable including the security indicator and the information related to the security indicator in the community-based security information of the community.

Abstract: In some examples, a system receives, from a sender, an access control value generated based on information of a plurality of recipients. The system sends, to the sender, a signed version of the access control value for sending by the sender to the plurality of recipients with an encrypted message. The system receives, from a first recipient a request for a key to decrypt the encrypted message, a signed access control value and recipient information for deriving the access control value. The system determines whether the first recipient is one of the plurality of recipients using the signed access control value and the recipient information.

Abstract: Techniques for using padding in format preserving encryption are provided. In one aspect, it may be determined if padding of a plaintext undergoing format preserving encryption is needed. A pseudo random padding length may be calculated when it is determined that padding is needed. The calculated length of padding may be added to the plaintext when it is determined that padding is needed. The plaintext and added padding may be encrypted using format preserving encryption to create a cipher text.