GB2276965A - Protecting temporarily stored data. - Google Patents
Protecting temporarily stored data. Download PDFInfo
- Publication number
- GB2276965A GB2276965A GB9406576A GB9406576A GB2276965A GB 2276965 A GB2276965 A GB 2276965A GB 9406576 A GB9406576 A GB 9406576A GB 9406576 A GB9406576 A GB 9406576A GB 2276965 A GB2276965 A GB 2276965A
- Authority
- GB
- United Kingdom
- Prior art keywords
- data
- session
- memory
- key
- ciphering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
- G06F21/60—Protecting data
- G06F21/62—Protecting access to data via a platform, e.g. using keys or access control rules
Abstract
An arrangement for storing data (e.g. swapfiles) in computer equipment (4) comprising a first memory location (1), e.g. a volatile memory, for temporary storage of data for instance for the time of processing, and a second memory location (2), e.g. a non-volatile memory, for longer-term storage of data when desired. Ciphering means (3) converts the data into an encrypted mode with an exchangeable encryption key and into a decrypted mode by a corresponding decryption key. The arrangement also comprises a ciphering key generator (7) for generating at least one random encryption key (5) and a corresponding decryption key (6) for each discrete session. The encryption and decryption keys (5, 6) am retained during a session and their use is prevented after completion of the session, e.g. because they were stored in the volatile memory. <IMAGE>
Description
AN ARRANGEMENT FOR STORING DATA IN COMPUTER EQUIPNENT
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for storing data in computer equipment comprising a first memory location, e.g. a volatile memory, for temporary storage of data for instance for the time of processing, and a second memory location, e.g. a non-volatile memory, for longer-term storage of data when desired, and ciphering means for converting the data into an encrypted mode with an encryption key and respectively into a decrypted mode by a decryption key.
Computers make use of non-volatile memories, such as disk memories, for storing data files to be retained only temporarily - e.g. swap files -, since the use of volatile system memories, such as RAN memories, is often costly.
Even though temporary data files are retained in a non-volatile memory, they nevertheless are only needed during one session, in other words, during the working period of a user or when computer programs using such data files are run. By a session is meant in this context for example continuous performing of interactive data processing. A session may be contemplated to begin for instance with log-in and to end with log-off. Many computers retain data stored in temporary files in their non-volatile memory. This creates a security problem, since the content of old temporary data files may be retrieved from the non-volatile memory and thus unauthorized persons can access to confidential data possibly stored in such data files. Some computer equipment clear the temporary data files from the non-volatile memory to solve this problem. However, this is of no avail if an attempt is made to read the non-volatile memory before clearing, for instance when the computer has come to an abnormal halt in the midst of a session.
A known method for assuring security is to use ciphering. The data files can be converted into encrypted mode with an encryption program by giving the program an encryption key when the data is written, and the data can be converted into a decrypted mode using the same or another decryption key dependent on the encryption key employed when the data is read. Encryption systems typically require some manner of ciphering key management, to enable safe development, transmission and storage of keys.
It is an object of the present invention to provide a novel arrangement for storing data in computer equipment when data to be retained non-permanently is stored, with which arrangement particularly problems relating to ciphering key management can be substantially eliminated. This is achieved with the arrangement of the invention, comprising a ciphering key generator for generating at least one random encryption key and a corresponding decryption key for each discrete session for use in the cyphering means to encrypt data to be stored non-permanently prior to its storage in the second memory location and respectively to convert it into decrypted mode after reading from the second memory location, and means for retaining the generated encryption and decryption keys during a session and for destroying them after completion of the session at the latest. The basic idea of the invention is that the computer equipment itself generates the encryption and decryption keys that it uses for storing data to be temporarily retained in a non-volatile memory location.
In this way, these encryption and decryption keys are only known to the computer itself. Since the encryption and decryption of data is performed wholly automatically and independently by the computer itself, these operations are fully transparent to the user. However, at the end of the session at the latest the encryption and decryption keys are destroyed, for example erased from the volatile memory, and thus data possibly stored in the non-volatile memory location and intended only for temporary storage can no longer be deciphered. This procedure assures complete safety even for such temporarily stored data.
The encryption and decryption keys may be generated session-specifically, in which case the same encryption and decryption keys are used for the entire session (these keys may naturally also be the same depending on the ciphering program). Alternatively, encryption and decryption keys may be generated separately for each data file. In cases where several programs are executed during a session, the keys may be destroyed program-specifically, in which event exit from the program causes destroying of the keys.
For a better understanding of the present invention and to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawing.
The figure shows at reference 4 computer equipment comprising a volatile memory location 1 which is the memory of the data processing section, such as a volatile memory or processor register. The computer equipment 4 further comprises a second memory location 2 which is a non-volatile memory and provides a storage area for possibly more permanent storing. Typically such a non-volatile memory location is a hard disk. This embodiment specifically relates to safe storage of temporarily stored data or data files in this memory location 2, and thus the figure only concerns storage of such temporarily stored data or data files in said non-volatile memory location 2. For clarity, other storage executed by the computer equipment 4 has not been shown in the figure.
Ciphering means 3 are provided on the data storage and reading route between memory location 1 and memory location 2. Data is stored from memory location 1 to memory location 2 on the one hand and read from memory location 2 to memory location 1 on the other hand through these ciphering means. The encryption and decryption keys 5 and 6 required for these ciphering means 3 are generated by a ciphering key generator 7. This ciphering key generator 7 operates independently and generates the encryption and decryption keys as randomly as possible.
These encryption and decryption keys are stored in storage means 8. Generation of the encryption and decryption keys is either session-related, data file-related or application-related. However, it is necessary that the encryption and decryption keys 5 and 6 are retained in storage means 8 only for the time for which the temporary data files or temporarily stored data encrypted by means of them must be available, that is, until the end of the session at the most. Thereafter the data stored using these random ciphering keys in the non-volatile memory location 2 can no longer be deciphered, since the key employed for their encryption has been destroyed from means 8. In practice this can mean for instance that the encryption key and the corresponding decryption key are stored in the volatile memory wherefrom they are lost when power is switched off from the memory circuit in question for instance at the end of a session.
The basic idea of the invention, according to which the encryption and decryption keys must no longer be available after the session, can also be realized in other manners than that contemplated above. The encryption and decryption keys may be selected randomly for example from a large group of alternative keys permanently stored in the microprocessor. In that case, the procedure can be such that the keys can no longer be accessed after the session, even if they existed physically. Also other methods for storing keys protected in a corresponding manner are possible within the scope of the present invention.
The figure shows as exterior connections interfacing to the computer equipment 4 a user on the one hand and a protected system on the other hand. These are naturally only exemplary user interfaces. The protected system has been indicated as a user interface because by means of the shown computer equipment 4 data temporarily transferred from the protected system for purposes of processing or editing into computer equipment 4 and possibly temporarily stored therein in that connection can be kept protected.
This is based on the fact that no decipherable remnants of processed data can remain in the computer equipment 4 after the processing of such protected data therein has been completed.
The arrangement of the invention has been described in the above with reference to one exemplary embodiment, and it is to be understood that equipment-related and computer-related modifications may be made therein without departing from the scope of the invention. A feature of the invention is that, in connection with temporary storage of data, an encryption key known only to the computer itself may be employed and, furthermore, that this key is destroyed by the computer itself or can otherwise no longer be accessed when said temporarily stored data is no longer needed.
Claims (5)
1. A system for storing data in a computer during a
computing session and comprising a first memory means
suitable for short term storage of data, a second
memory means suitable for longer term storage of data,
a ciphering key generator for generating at least one
random encryption key and at least one corresponding
decryption key for the session, ciphering means for
converting data read from the first memory means,
prior to storage in the second memory means into an
encrypted form using the or each encryption key and
for converting encrypted data read from the second
memory into a decrypted form using the or each
decryption key, and means for retaining the encryption
and decryption keys during the session and for
preventing their use after completion of the session.
2. A system according to claim 1, wherein the first
memory means is a volatile memory.
3. A system according to claim 1 or 2, wherein the second
memory means is a non-volatile memory.
4. An arrangement for storing data in computer equipment
comprising
a first memory location, e.g. a volatile memory,
for temporary storage of data for instance for the
time of processing;
a second memory location, e.g. a non volatile
memory for longer-term storage of data when desired;
ciphering means for converting the data into an
encrypted mode with an exchangeable encryption key and
into a decrypted mode with a corresponding decryption
key, said arrangement comprising
a ciphering key generator for generating at least
one random encryption key and a corresponding
decryption key for each discrete session for use in
the ciphering means to encrypt data to be stored
non-permanently prior to its sotrage in the second
memory location and respectively to convert it into
decrypted mode after reading from the second memory
location; and
means for retaining'the generated encryption and
decryption keys during a session and for preventing
their use after completion of the session.
5. A system for storing data in a computer substantially
as hereinbefore described with reference to the
accompanying drawing.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI931530A FI93280C (en) | 1993-04-05 | 1993-04-05 | An arrangement for storing data on computer hardware |
Publications (3)
Publication Number | Publication Date |
---|---|
GB9406576D0 GB9406576D0 (en) | 1994-05-25 |
GB2276965A true GB2276965A (en) | 1994-10-12 |
GB2276965B GB2276965B (en) | 1997-07-09 |
Family
ID=8537685
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9406576A Expired - Fee Related GB2276965B (en) | 1993-04-05 | 1994-03-31 | An arrangement for storing data in computer equipment |
Country Status (2)
Country | Link |
---|---|
FI (1) | FI93280C (en) |
GB (1) | GB2276965B (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2366631A (en) * | 2000-03-04 | 2002-03-13 | Ericsson Telefon Ab L M | A communication node and a method of recovering security data following a power failure |
US6941456B2 (en) * | 2001-05-02 | 2005-09-06 | Sun Microsystems, Inc. | Method, system, and program for encrypting files in a computer system |
EP1008249A4 (en) * | 1996-01-16 | 2005-09-21 | Symantec Corp | System for decryption and re-encryption of files |
US7131010B2 (en) | 2000-07-24 | 2006-10-31 | Sony Corporation | Data processing system, data processing method, data processing apparatus, and program providing medium |
WO2006135999A1 (en) * | 2005-06-24 | 2006-12-28 | Research In Motion Limited | System and method for managing memory in a mobile device |
US7321660B2 (en) | 2002-04-18 | 2008-01-22 | Hewlett-Packard Development Company, L.P. | Method and apparatus for encrypting/decrypting data using timed-release keys |
CN100517417C (en) * | 2001-07-25 | 2009-07-22 | 松下电器产业株式会社 | Deciphering equipment, deciphering equipment making method and providing system |
US7594276B2 (en) | 1998-03-24 | 2009-09-22 | Symantec Corporation | Bubble-protected system for automatic decryption of file data on a per-use basis and automatic re-encryption |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2163577A (en) * | 1984-08-23 | 1986-02-26 | Nat Res Dev | Software protection device |
GB2247548A (en) * | 1990-08-13 | 1992-03-04 | Marconi Gec Ltd | Data security system |
-
1993
- 1993-04-05 FI FI931530A patent/FI93280C/en active
-
1994
- 1994-03-31 GB GB9406576A patent/GB2276965B/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2163577A (en) * | 1984-08-23 | 1986-02-26 | Nat Res Dev | Software protection device |
GB2247548A (en) * | 1990-08-13 | 1992-03-04 | Marconi Gec Ltd | Data security system |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1008249A4 (en) * | 1996-01-16 | 2005-09-21 | Symantec Corp | System for decryption and re-encryption of files |
US7594276B2 (en) | 1998-03-24 | 2009-09-22 | Symantec Corporation | Bubble-protected system for automatic decryption of file data on a per-use basis and automatic re-encryption |
GB2366631A (en) * | 2000-03-04 | 2002-03-13 | Ericsson Telefon Ab L M | A communication node and a method of recovering security data following a power failure |
GB2366631B (en) * | 2000-03-04 | 2004-10-20 | Ericsson Telefon Ab L M | Communication node, communication network and method of recovering from a temporary failure of a node |
US7131010B2 (en) | 2000-07-24 | 2006-10-31 | Sony Corporation | Data processing system, data processing method, data processing apparatus, and program providing medium |
US6941456B2 (en) * | 2001-05-02 | 2005-09-06 | Sun Microsystems, Inc. | Method, system, and program for encrypting files in a computer system |
CN100517417C (en) * | 2001-07-25 | 2009-07-22 | 松下电器产业株式会社 | Deciphering equipment, deciphering equipment making method and providing system |
US7321660B2 (en) | 2002-04-18 | 2008-01-22 | Hewlett-Packard Development Company, L.P. | Method and apparatus for encrypting/decrypting data using timed-release keys |
WO2006135999A1 (en) * | 2005-06-24 | 2006-12-28 | Research In Motion Limited | System and method for managing memory in a mobile device |
Also Published As
Publication number | Publication date |
---|---|
FI931530A0 (en) | 1993-04-05 |
FI93280C (en) | 1995-03-10 |
GB2276965B (en) | 1997-07-09 |
FI93280B (en) | 1994-11-30 |
GB9406576D0 (en) | 1994-05-25 |
FI931530A (en) | 1994-10-06 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20050331 |