SYSTEMS FOR EMBEDDING INFORMATION IN DATA STRINGS

• US 20100284532A1
• Filed: 05/05/2009
• Published: 11/11/2010
• Est. Priority Date: 05/05/2009
• Status: Active Grant

• Current Assignee: Micro Focus LLC (Open Text Corporation)
• Original Assignee: Voltage Security LLC (Open Text Corporation)
• Inventors: Burnett, Steven D., Vaterlaus, Robert K., Martin, Luther W., Pauker, Matthew J., Spies, Terence
• Granted Patent: US 8,948,375 B2
• Time in Patent Office: Days
• US Class Current: 380/28
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/6227 where protection concerns the structure of data, e.g. records, types, queries
• CPC Class Codes: G06F 21/6245 Protecting personal data, e.g. for financial or medical purposes
• CPC Class Codes: H04L 2209/24 Key scheduling, i.e. generating round keys or sub-keys for block encryption
• CPC Class Codes: H04L 9/0625 with splitting of the data block into left and right halves, e.g. Feistel based algorithms, DES, FEAL, IDEA or KASUMI
• CPC Class Codes: H04L 9/0816 Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use

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.

Claims

1. A computer-implemented method for embedding information in a data string, comprising:

with computing equipment, obtaining an original data string containing characters, wherein each character in the original data string belongs to a first set of characters; and

with the computing equipment, embedding information in the original data string to produce an augmented data string containing characters belonging to a second set of characters, wherein the number of characters in the second set of characters is greater than the number of characters in the first set of characters.

2. The method defined in claim 1, wherein embedding information in the data string further comprises:

with a map that maps each of characters in the second set of characters to one of the characters in the first set of characters, replacing at least one character of the original data string with a character belonging to the second set of characters, wherein the information is encoded by the character belonging to the second set of characters.

3. The method defined in claim 2, wherein each of the characters in the first set of characters maps to at least two characters in the second set of characters.

4. The method defined in claim 1, wherein the first set of characters is a subset of the second set of characters.

5. The method defined in claim 1, wherein the first set of characters comprises numerical characters and wherein the second set of characters comprises numerical characters and letter characters.

6. A computer-implemented method for embedding information in a data string encoded with characters in a first set of characters, comprising:

with computing equipment, recoding the data string in a second set of characters that is larger than the first set of characters to produce a shortened data string that is shorter than the data string encoded with characters in the first set of characters; and

with the computing equipment, embedding information by adding characters to the shortened data string to produce an augmented data string of equal length to the data string encoded with characters in the first set of characters.

7. The method defined in claim 6, wherein the first set of characters is a subset of the second set of characters.

8. The method defined in claim 6, wherein the second set of characters is a set of characters specified by a data type of the data string.

9. A computer-implemented method for encrypting and embedding information in a data string containing characters in a first set of characters, comprising:

with computing equipment, encrypting the data string using format-preserving encryption to produce an encrypted data string; and

with the computing equipment, embedding information in the encrypted data string to produce an augmented data string containing characters in a second set of characters, wherein the number of characters in the second set of characters is greater than the number of characters in the first set of characters.

10. The method defined in claim 9, further comprising:

prior to encrypting the data string, processing the data string with the computing equipment to remove extraneous characters from the data string.

11. The method defined in claim 9, wherein encrypting the data string comprises:

encoding the data string using at least one index of sequential index values each of which corresponds to a respective one of the characters in the first set of characters;

encrypting the encoded data string using a format-preserving cipher; and

using the index, decoding the encrypted encoded data string to produce a decoded encrypted data string with characters in the first set of characters.

12. The method defined in claim 11, wherein embedding information comprises:

recoding the decoded encrypted data string in the second set of characters to produce a shortened string that is shorter than the decoded encrypted data string; and

adding characters to the shortened data string to produce an augmented data string, wherein the added characters represent the information being embedded and wherein the augmented data string and the data string have the same length.

13. The method defined in claim 9, wherein embedding the information further comprises:

with a map that maps each of the characters in the second set of characters to one of the characters in the first set of characters, replacing at least one character of the encrypted data string with a character in the second set of characters, wherein the information is encoded by the character in the second set of characters.

14. The method defined in claim 13, wherein each of the characters in the first set of characters maps to at least two characters in the second set of characters and wherein the first set of characters is a subset of the second set of characters.

15. The method defined in claim 9, wherein the format-preserving encryption uses a cryptographic key and wherein the information that is embedded comprises a version number for the cryptographic key.

16. The method defined in claim 9, wherein the first set of characters has only ten characters and the second set of characters has only thirty six characters.

17. The method defined in claim 9, wherein the first set of characters has only numerical characters.

18. The method defined in claim 17, wherein the second set of characters has only numerical and letter characters.

19. A computer-implemented method for encrypting and embedding information in a data string containing characters in a first set of characters, comprising:

with computing equipment, encoding the data string using at least one index of sequential index values each of which corresponds to a respective one of the characters in the first set of characters;

with the computing equipment, encrypting the encoded data string using a format-preserving cipher to produce an encrypted encoded data string;

with the computing equipment, embedding information in the encrypted encoded data string to produce an augmented encrypted encoded data string; and

with the computing equipment, using at least one additional index of sequential index values, decoding the augmented encrypted encoded data string to produce an augmented encrypted data string that contains characters in a second set of characters, wherein the second set of characters has a greater number of characters than the first set of characters.

20. The method defined in claim 19, further comprising:

prior to encoding, processing the data string with the computing equipment to remove extraneous characters from the data string, wherein the processed data string contains characters from the first set of characters.

21. The method defined in claim 19, wherein the augmented encrypted data string is of equal length to the data string containing characters in the first set of characters and wherein embedding the information comprises:

adding additional characters to the encrypted encoded data string so that the augmented encoded data string is greater in length than the encrypted encoded data string.

22. The method defined in claim 19, wherein the encoded data string is a hex number.