Data cryptography operations using control vectors

• US 4,918,728 A
• Filed: 08/30/1989
• Issued: 04/17/1990
• Est. Priority Date: 08/30/1989
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yeh, Phil C., Johnson, Donald B., Karne, Ramesh K., Thomas, Julian, Matyas, Stephen M., Abraham, Dennis G., Prymak, Rostislaw, Le, An V., Wilkins, John D.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/401,486
• Time in Patent Office: 230 Days
• Field of Search: 380/21, 380/25, 380/45, 380/47, 380/49, 380/23, 380/24
• US Class Current: 380/280
• CPC Class Codes: G06F 9/30007 to perform operations on data operands
• CPC Class Codes: G06F 9/30018 Bit or string instructions
• CPC Class Codes: G06F 9/3004 to perform operations on memory
• CPC Class Codes: G06F 9/3885 using a plurality of independent parallel functional units
• CPC Class Codes: G06F 9/3895 for complex operations, e.g. multidimensional or interleaved address generators, macros
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 2209/20 Manipulating the length of blocks of bits, e.g. padding or block truncation
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/0827 involving distinctive intermediate devices or communication paths network architectures or network communication protocols using different networks H04L63/18
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

Data cryptography is achieved in an improved manner by associating with the data cryptography key, a control vector which provides the authorization for the uses of the key intended by the originator of the key. Among the uses specified by the control vector are limitations on encryption, decryption, authentication code generation and verification, translation of the user'"'"'s data. Complex combinations of data manipulation functions are possible using the control vectors, in accordance with the invention. The system administrator can exercise flexibility in changing the implementation of his security policy by selecting appropriate control vectors in accordance with the invention. Complex scenarios such as encrypted mail box, session protection, file protection, ciphertext translation center, peer-to-peer ciphertext translation, message authentication, message authentication with non-repudiation and many others can be easily implemented by a system designer using the control vectors, in accordance with the invention.

Claims

1. In a data processing system which processes cryptographic service requests for performing data cryptography functions on data using cryptographic keys which are associated with control vectors defining the functions which each key is allowed by its originator to perform, an apparatus for validating that the data cryptography functions requested for a cryptographic key have been authorized by the originator of the key, comprising:

a cryptographic facility characterized by a secure boundary through which passes an input path for receiving said cryptographic service requests, data, cryptographic keys and their associated control vectors, and an output path for providing responses thereto, there being included within said boundary a cryptographic control means coupled to said input path, a control vector checking means and a cryptographic processing means coupled to said control means, and a master key storage coupled to said processing means, for providing a secure location for executing data cryptography functions in response to said received service requests;

said cryptographic control means receiving over said input path a cryptographic service request for performing a data cryptography function with a cryptographic key;

said control vector checking means having an input coupled to said input path for receiving a control vector associated with said cryptographic key and an input coupled to said cryptographic control means, for receiving control signals to initiate checking that said control vector authorizes the data cryptographic function which is requested by said cryptographic service request;

said control vector checking means having an authorization output coupled to an input of said cryptographic processing means, for signalling that said data cryptography function is authorized, the receipt of which by said cryptographic processing means initiates the performance of the requested data cryptography function with said cryptographic key.

2. The apparatus of claim 1, which further comprises:

a cryptographic key storage means coupled to said cryptographic facility over said input and output paths, for storing said cryptographic key in an encrypted form in which said cryptographic key is encrypted under a storage key which is a logical product of said associated control vector and a master key stored in said master key storage;

said cryptographic control means receiving over said input path a cryptographic service request for performing a data cryptographic function which includes recovering said cryptographic key from said cryptographic key storage means and said control vector checking means outputting in response thereto, an authorization signal to said cryptographic processing means that the requested data cryptographic function is authorized;

said cryptographic processing means operating in response to said authorization signal, to receive said encrypted form of said cryptographic key from said cryptographic key storage means and to decrypt said encrypted form under said storage key whichis a logical product of said associated control vector and said master key stored in said master key storage;

said cryptographic processing means further operating in response to said authorization signal, to receive said data from said input path and to complete performing the requested data cryptography function on said data with said cryptographic key.

3. The apparatus of claim 2, wherein said storage key is the exclusive-OR product of said associated control vector and said master key stored in said master key storage.

4. The apparatus of claim 2, wherein said associated control vector is stored with said encrypted form of said cryptographic key in said cryptographic key storage means.

5. The apparatus of claim 1, wherein said associated control vector includes fields defining authorized types of cryptographic functions including key management functions, data cryptography functions and PIN processing functions, and the data cryptography functions type is designated.

6. The apparatus of claim 5, wherein said associated control vector includes fields defining export control and usage.

7. The apparatus of claim 2, wherein said associated control vector includes a type field designating that said cryptographic key can perform data cryptography functions and further includes an export control field which designates whether said local data processing system is allowed to export said cryptographic key and further designates whether a remote data processing system to which said local data processing system is connected, is allowed to reexport said cryptographic key.

8. The apparatus of claim 1, wherein said associated control vector includes a type field designating that said cryptographic key can perform data cryptography functions and further includes a subtype field designating that said cryptographic key can perform data privacy functions.

9. The apparatus of claim 8, wherein said associated control vector further includes a usage field designating that said cryptographic key can perform encryption of said data.

10. The apparatus of claim 8, wherein said associated control vector further includes a usage field designating that said cryptographic key cannot perform encryption of said data.

11. The apparatus of claim 8, wherein said associated control vector further includes a usage field designating that said cryptographic key can perform decryption of said data.

12. The apparatus of claim 8, wherein said associated control vector further includes a usage field designating that said cryptographic key cannot perform decryption of said data.

13. The apparatus of claim 1, wherein said associated control vector includes a type field designating that said cryptographic key can perform data cryptography functions and further includes a subtype field designating that said cryptographic key can perform message authentication functions.

14. The apparatus of claim 13, wherein said associated control vector further includes a usage field designating that said cryptographic key can be used to generate a message authentication code on said data.

15. The apparatus of claim 13, wherein said associated control vector further includes a usage field designating that said cryptographic key cannot be used to generate a message authentication code on said data.

16. The apparatus of claim 13, wherein said associated control vector further includes a usage field designating that said cryptographic key can be used to verify a message authentication code on said data.

17. The apparatus of claim 13, wherein said associated control vector further includes a usage field designating that said cryptographic key cannot be used to verify a message authentication code on said data.

18. The apparatus of claim 1, wherein said associated control vector includes a type field designating that said cryptographic key can perform data cryptography functions and further includes a subtype field designating that a translate ciphertext function can be performed by said cryptographic key.

19. The apparatus of claim 18, wherein said associated control vector further includes a usage field designating that said cryptographic key can be used as the output data key in a translate ciphertext function.

20. The apparatus of claim 18, wherein said associated control vector further includes a usage field designating that said cryptographic key cannot be used as the output data key in a translate ciphertext function.

21. The apparatus of claim 18, wherein said associated control vector further includes a usage field designating that said cryptographic key can be used as the input data key in a translate ciphertext function.

22. The apparatus of claim 18, wherein said associated control vector further includes a usage field designating that said cryptographic key cannot be used as the input data key in a translate ciphertext function.

23. The apparatus of claim 1, wherein said associated control vector includes a type field designating that said cryptographic key can perform data cryptography functions and further includes a subtype field designating that said cryptographic key is an ANSI data key.

36. The apparatus of claim 1, which further comprises:

a working key storage within said cryptographic facility coupled to said cryptographic processing means, for providing a secure location for the storage of working keys.

37. The apparatus of claim 36, which further comprises:

said working key storage storing a plurality of working keys and their associated control vectors in clear text form.

38. The apparatus of claim 37, which further comprises:

said cryptographic facility receiving over said input path a cryptographic service request for performing a data cryptography function;

said control vector checking means checking the associated control vector accessed from said working key storage and outputting an authorization signal to said cryptographic processing means that said cryptographic service request is authorized using the respective key accessed from said working key storage.

39. The apparatus of claim 37, which further comprises:

said working keys being stored in said working key storage as the exclusive-OR product of each key with its respective control vector.

40. The apparatus of claim 39, which further comprises:

said cryptographic facility receiving over said input path a cryptographic service request for performing a data cryptography function and also receiving the corresponding associated control vector which undergoes control vector checking in said control vector checking means;

said control vector checking means outputting an authorization signal to said cryptographic processing means that said cryptographic service request is authorized, said corresponding exclusive-OR product of the control vector and its respective key then being exclusive-ORed with said control vector in order to recover the key for the requested cryptographic operation.

41. The apparatus of claim 1, which further comprises:

a working key storage within said cryptographic facility, for storing working keys in clear text form and for storing their respective associated control vectors;

said cryptographic control means receiving over said input path a cryptographic service request for performing a data cryptography function which includes accessing said cryptographic key and said associated control vector from said working key storage and said control vector checking means outputting in response thereto, an authorization signal to said cryptographic processing means that the requested data cryptography function is authorized;

said cryptographic processing means operating in response to said authorization signal, to complete performing the requested data cryptography function on said data with said cryptographic key.

42. The apparatus of claim 1, which further comprises:

a working key storage within said cryptographic facility coupled to said cryptographic processing means, for storing the exclusive-OR product of working keys and their associated control vectors;

said cryptographic control means receiving over said input path a cryptographic service request and the corresponding associated control vector, for performing a data cryptography function;

said control vector checking means checking said control vector and outputting in response thereto, an authorization signal to said cryptographic processing means that the requested data cryptography function is authorized;

said cryptographic processing means operating in response to said authorization signal, to perform an exclusive-OR operation between said control vector and said product which has been accessed from said working key storage, yielding said working key in clear text form;

said cryptographic processing means further operating in response to said authorization signal, to complete performing the requested data cryptography function with said cryptographic key.

24. In a data processing system which processes cryptographic service requests for the performance of data cryptography functions on data using cryptographic keys which are associated with control vectors defining the functions which each key is allowed by its originator to perform, a method for validating that data cryptography functions requested for a cryptographic key have been authorized by the originator of the key, comprising the steps of:

receiving a cryptographic service request for performing a data cryptography function on data using a cryptographic key in a cryptographic facility characterized by a source boundary through which passes an input path and an output path;

receiving a control vector associated with said cryptographic key and checking that said control vector authorizes the data cryptography function which is requested by said cryptographic service request;

signalling that said data cryptography function is authorized and initiating the performance of the requested data cryptography function with said cryptographic key.

25. The method of claim 24, which further comprises the steps of:

storing in a storage means said cryptographic key in an encrypted form in which said cryptographic key is encrypted under a storage key which is a logical product of said associated control vector and a master key.

26. The method of claim 24, wherein said associated control vector includes fields defining authorized types of cryptographic functions including key management functions, data cryptography functions and PIN processing functions, and the data cryptography functions type is designated.

27. The method of claim 24, wherein said data cryptography function is session protection to protect the confidentiality of data transmissions between two communicating devices in said system which share a common data encrypting/decrypting key, permitting each said device to both send and receive encrypted data, further comprising the steps of:

sharing a data privacy key between said devices;

storing said data privacy key in operational form encrypted under a master key at each respective device;

providing usage attributes for the control vector of each data privacy key for enciphering and deciphering, respectively, which enables each key to be used to both encipher and decipher data.

28. The method of claim 24, wherein said data cryptography function is file protection to protect the confidentiality of data files, wherein a single end user of said system possesses a data encrypting/decrypting key permitting data to be encrypted for storage and to be decrypted for purposes of recovery of the file, further comprising the steps of:

providing a data privacy key to said single end user;

storing an encrypted form of said data privacy key with data which has been encrypted thereby;

said data privacy key being stored in import form encrypted under a key encrypting key, with its associated control vector;

providing usage attributes for the control vector of said data privacy key for enciphering and deciphering, thereby permitting the data file to be both encrypted and decrypted with the same key.

29. The method of claim 24, wherein said data cryptography function is an encrypted mail box in which each of a plurality of users of said system has a data privacy key in two forms, a first form permitting data encryption and a second form permitting data decryption, the first form of the key being placed in the public directory accessible to all said users of the mail box so that each registered key is recorded under a user identifier belonging to one of said users who registers the key, the second form of the key being private to said one of said users to which it belongs, so that mail deposited in the mail box directed to said one of said users in its encrypted form, can be decrypted only by said one of said users who is the intended recipient, further comprising the steps of:

providing a data privacy key which has been generated in two forms, a first form permitting enciphering only and a second form permitting deciphering;

providing control vector usage attributes for the control vector associated with said data privacy key, which has for the first form of the data privacy key encipher only features and which has for the second form of the data privacy key decipher features.

30. The method of claim 24, wherein said data cryptography function is a ciphertext translation function to be performed at a ciphertext translation center in a network in said system capable of securely translating encrypted data from encryption under a first data key to encryption under a second data key, further comprising the steps of:

generating a data key in two forms at a plurality of devices in a communications network in said system, a first form being a data privacy key in operational form having an associated control vector which has encipher and decipher attributes, and a second form of the data key being a data translate key in the export form, suitable for export to a ciphertext translation center in the network;

receiving the data translate key at the ciphertext translation center and converting the received data translation key to an operational form, the control vector associated with said data translation key having both translate-in and translate-out attributes;

enciphering data at a first device in said network which is transmitted to said ciphertext translation center where it is translated to encipherment under said second data key known to a second device in the network connected to said ciphertext translation center;

transmitting said translated data from said center to said second device where it is deciphered under said second data key.

31. The method of claim 30, wherein said ciphertext translation center cannot decrypt received inbound encrypted data nor can it encrypt data in a form comparable to outbound encrypted data.

32. The method of claim 24, wherein said data cryptography function is a peer-to-peer ciphertext translation for a communications network chain in said system which includes a first device which originates a communication, connected to a first ciphertext translation center which in turn is connected to a second ciphertext translation center which in turn is connected to a second network device, for a transmission of encrypted data from said first device through said first and second ciphertext translation centers to said second device, further comprising the steps of:

generating a first data key in said first network device in two forms, a first form being a data privacy key in operational form having an associated control vector which has encipher attributes, and a second form of said first data key being a data translate-in key in the export form, suitable for export to said first ciphertext translation center;

generating a second data key in said second network device in two forms, a first form being a data privacy key in operational form having an associated control vector which has decipher attributes, and a second form of said second data key being a data translate-out key in export form, suitable for export to said second ciphertext translation center;

generating a third data key in said first ciphertext translation center in two forms, a first form being a data translate-out key and a second form being a data translate-in key, suitable for export to said second ciphertext translation center;

said first network device transmitting said first data key in its second form as a translate-in key to said first ciphertext translation center;

said second network device transmitting said second data key in its second form as a translate-out key to said second ciphertext translation center;

said first ciphertext translation center transmitting said third data key in its second form as a translate-in key to said second ciphertext translation center;

said first network device encrypting data under said first data key in said first form and transmitting the encrypted data to said first ciphertext translation center where the data is translated under said first data key in said second form to be encrypted under said third data key in said first form to be translated out and transmitted to said second ciphertext translation center where the data is translated under said third data key in its second form into a form encrypted under said second data key in its second form where it is translated out and transmitted to said second network device where the data is then decrypted under said second data key in its first form.

33. The method of claim 24, wherein said data cryptography function is applied to an encrypted file under a first key so that a portion of the file can be re-encrypted under a second key for transmission to an intended receiver, without revealing the entire encrypted file, further comprising the steps of:

generating a first data key in two forms at a first device in said system, a first form being a data privacy key stored in operational form and a second form being a data translate-in key;

encrypting a data file using said data privacy key and storing said file in its encrypted form in a data storage device;

said first device generating a second data key in two forms, a translate-out key and a data decryption key;

transmitting said data decryption key to a second device in said system connected to said first device;

accessing said data file from said data storage device and re-enciphering a portion of said file from encipherment under said first data key to encipherment under said second data key via a translate ciphertext instruction using said first data key in said translate-in form and said second data key in said translate-out form, and transmitting said re-enciphered portion of said data file from said first device to said second device;

decrypting said transmitted portion of said data file by means of said decryption key form of said second key for use at said second device.

34. The method of claim 24, wherein said data cryptography function is message integrity, wherein the contents of a message is protected from unauthorized modification, further comprising the steps of:

providing a data/MAC key and an associated control vector having MAC generation and MAC verification attributes at both a sending station and a receiving station in a communications network in said system;

computing an MAC value for a message to be sent from the sending station to the receiving station, employing said data/MAC key and said control vector at said sending station;

transmitting said message and said computed MAC value from said sending station to said receiving station;

computing a second MAC value on said received message at said receiving station, employing said data/MAC key and said control vector and comparing said second computed MAC value with said transmitted MAC value;

verifying the integrity of the message received at said receiving station when said two computed MAC values are equal.

35. The method of claim 24, wherein said data cryptography function is message authentication with non-repudiation, further comprising the steps of:

providing a data/MAC key with a first associated control vector having an MAC generation attribute at a sending station in a communications network in said system;

providing said data/MAC key with a second control vector having an MAC verification attribute but not having an MAC generation attribute, at a receiving station in said communications network in said system;

computing a first value for the MAC on a message to be sent by said sending station over said communications network to said receiving station, using the said data/MAC key and said first control vector at said sending station;

transmitting said message and said first MAC value from said sending station over said communications network to said receiving station;

computing a second value for said MAC on said message received at said receiving station, using said data/MAC key and said second control vector, at said receiving station;

verifying that said message has integrity and that it was sent by said sending station, when said first value for said MAC equals said second value for said MAC.

43. The method of claim 24, wherein said data cryptography function is a peer-to-peer ciphertext translation for a communications network in said system chain which includes a key issuing device in the network, a first device which originates a communication, connected to a first ciphertext translation center which in turn is connected to a second ciphertext translation center which in turn is connected to a second network device, for a transmission of encrypted data from said first device through said first and second ciphertext translation centers to said second device, further comprising the steps of:

generating a first data key in said first network device in two forms, a first form being a data privacy key in operational form having an associated control vector which has encipher attributes, and a second form of said first data key being a data translate-in key in the export form, suitable for export to said first ciphertext translation center;

generating a second data key in said second network device in two forms, a first form being a data privacy key in operational form having an associated control vector which has decipher attributes, and a second form of said second data key being a data translate-out key in export form, suitable for export to said second ciphertext translation center;

generating a third data key in said key issuing device in two forms, a first form being a data translate-out key suitable for export to said first ciphertext translation center and the second form being a data translate-in key, suitable for export to said second ciphertext translation center;

said first network device transmitting said first data key in its second form as a translate-in key to said first ciphertext translation center;

said second network device transmitting said second data key in its second form as a translate-out key to said second ciphertext translation center;

said first key issuing device transmitting said third data key in its first form as a translate-out key to said first ciphertext translation center and transmitting said third data key in its second form as a translate-in key to said second ciphertext translation center;

said first network device encrypting data under said first data key in its first form and transmitting the encrypted data to said first ciphertext translation center where the data is translated under said first data key in its second form to be encrypted under said third data key in its first form to be translated out and transmitted to said second ciphertext translation center where the data is translated under said third data key in its second form into a form encrypted under said second data key in its second form where it is translated out and transmitted to said second network device where the data is then decrypted under said second data key in its first form.