FR2846497A1 - Communal software word encryption key function having two units with register/first multiplexer/inverter and second multiplexer transmitting digital words with rotator separating words/second inverter - Google Patents

Abstract

The encryption key control unit has up and down digital word operations using initial values. Each of the first and second units has a register and first multiplexer with a first inverter. A second multiplexer transmits digital words with a rotator separating the words and a second inverter.

Description

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 The present invention relates to a key-forming device for a standard data encryption algorithm and, in particular, to an improved key-forming device for a standard data encryption algorithm that can provide keys for encryption and decryption. in a common software.

 It is thus a principal object of the present invention to implement a key training part for a standard data encryption algorithm that can be applied to all kinds of encryption systems in optimal hardware equipment.

 Another object of the present invention is to implement an encryption keying device and a key decrypting device in a common software for a standard data encryption algorithm.

 In order to achieve the above-described objects of the present invention, a key-forming device is created for a standard data encryption algorithm comprising a key control unit for producing up-data and down-data by performing operations for encryption and decryption by the use of an initial key value; a first shift unit for shifting the ascending data in a first direction; a second shift unit for shifting the descending data in the first direction; and a key training unit for generating keys for encryption and decryption for the standard data encryption algorithm by performing a Switched Choice 2 of the standard data encryption algorithm by using the shifted data in the data encryption algorithm. first shift unit and the second shift unit, characterized in that each of the first and second shift units comprises: a register, a first multiplexer for selectively transmitting to the register either the rising data

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 either the descending data and a counter-reaction data; a first inverse disposition unit for reverse arranging the register data; a second multiplexer for transmitting the register data during encryption and transmitting the data of the first reverse disposition unit during decryption; a rotator for shifting the data of the second multiplexer in a first direction in bit units; a second inverse disposition unit for reverse arranging the rotator data; and a third multiplexer for transmitting to the first multiplexer the rotator data as feedback data during encryption, and transmitting to the first multiplexer the data of the second reverse disposition unit as the counteraction data during decryption.

 In accordance with another aspect of the present invention, there is provided a key-forming device for a standard data encryption algorithm comprising: a key control unit for producing a rising data and a descendant data by performing operations for encryption and decryption by using an initial key value; a first shift unit for shifting up data; a second shift unit for shifting the descending data; and a key training unit for generating keys for encryption and decryption for the standard data encryption algorithm by performing a Switched Choice 2 of the standard data encryption algorithm by using the shifted data in the data encryption algorithm. first shift unit and the second shift unit, characterized in that each of the first and second shift units comprises: a register; a multiplexer for selectively transmitting to the register either the rising data or the falling data and a feedback data; and a rotator for shifting the register data in a first direction in bit units during encryption

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 and decrypting, and transmitting to the multiplexer the resulting data as feedback data.

 The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the following explanatory description made with reference to the accompanying drawings given solely by way of example illustrating the modes. embodiment of the invention and in which: - Figure 1 is a flowchart showing a standard general data encryption algorithm; FIG. 2 is a view showing a comparison of offset dimensions during encryption and decryption of the standard data encryption algorithm of FIG. 1; FIG. 3 is a block diagram illustrating a key forming device according to a first embodiment of the present invention; FIG. 4 is a block diagram illustrating a key control unit of FIG. 3; FIG. 5 is a block diagram illustrating a key forming device according to a second embodiment of the present invention; and FIG. 6 is a block diagram illustrating a key forming device according to a third embodiment of the present invention.

 Referring to FIG. 1, there is shown a standard general purpose data encryption algorithm which includes a data encryption portion 10 and a key formation portion 20.

 The data encryption portion 10 initially combines 64-bit input data, divides them into 32-bit right / left data, repeats 16-fold rounding to operate a function f and exclusive-OR operation using 48-bit keys (K i, i = 1, ..., 16) from the key-forming portion 20 and data exchange

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 right / left in each round, thus performing encryption.

 The operation of the key forming part 20 for encryption will now be explained with reference to FIG.

 An initial key is composed of 64 bits, and a parity bit is included in each position multiple of 8 in a row of bits. Thus, the parity bit is set so that each byte can have an odd number of '1'.

 First, Switched Choice 1 is performed on the original 64-bit key.

 Here, the parity bits are excluded, and only 56 bits are used for the Choice 1 Swapped.

 Table 1 shows a disposition state of the bits of the initial key conforming to the Choice 1 Switched.

TABLE 1

<Tb>
<tb> 57 <SEP> 49 <SEP> 41 <SEP> 33 <SEP> 25 <SEP> 17 <SEP> 9
<tb> 1 <SEP> 58 <SEP> 50 <SEP> 42 <SEP> 34 <SEP> 26 <SEP> 18
<tb> 10 <SEP> 2 <SEP> 59 <SEP> 51 <SEP> 43 <SEP> 35 <SEP> 27
<tb> 19 <SEP> 11 <SEP> 3 <SEP> 60 <SEP> 52 <SEP> 44 <SEP> 36
<tb> 63 <SEP> 55 <SEP> 47 <SEP> 39 <SEP> 31 <SEP> 23 <SEP> 15
<tb> 7 <SEP> 62 <SEP> 54 <SEP> 46 <SEP> 38 <SEP> 30 <SEP> 22
<tb> 14 <SEP> 6 <SEP> 61 <SEP> 53 <SEP> 45 <SEP> 37 <SEP> 29
<tb> 21 <SEP> 13 <SEP> 5 <SEP> 28 <SEP> 20 <SEP> 12 <SEP> 4
<Tb>

As shown in Table 1, the first bit obtained by the Permitted Choice 1 is equivalent to the 57th bit of the initial key, and the second bit of the resultant value is equivalent to the 49th bit of the initial key. Thus, the Switched Choice 1 changes the state of the bit disposition to the exclusion of the parity bits of the initial key.

 After that, the results of the Switched Choice 1 are divided by 28 bits and defined as CO and DO.

 Offset rounding is performed sequentially based on the CO and OD defined above.

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When it is assumed that the results of each shift rounding are defined as Ci and Di and that the condition 'i = 1, ..., 16' is satisfied, the results of each shift round Ci and Di are determined according to an offset dimension defined in Table 2.

Table 2

<Tb>
<tb> 1 <SEP> 1 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 10 <SEP> 11 <SEP > 12 <SEP> 13 <SEP> 14 <SEP> 15 <SEP> 16
<tb> Dimension <SEP> of <SEP> 1 <SEP> 1 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 1 <SEP> 2 <SEP > 2 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 1
<tb> @ hulling
<Tb>

Thus, C1 and D1 are produced by shifting CO and DO by 1 bit, C2 and D2 are produced by shifting C1 and D1 by 1 bit, and C3 and D3 are produced by shifting C2 and D2 by 2 bits.

 Ci (i = 1, ..., 16) and Di (1 = 1, ..., 16) can be obtained in the same way.

 After that, we make Choice 2 Switched using Ci (i = 1, ..., 16) and Di (i = 1, ..., 16) of each offset rounding, thus obtaining the keys Ki for the encryption.

 Table 3 shows a disposition status of the bits in accordance with Choice 2 switched.

Table 3

<Tb>
<tb> 14 <SEP> 17 <SEP> 11 <SEP> 24 <SEP> 1 <SEP> 5
<tb> 3 <SEP> 28 <SEP> 15 <SEP> 6 <SEP> 21 <SEP> 10
<tb> 23 <SEP> 19 <SEP> 12 <SEP> 4 <SEP> 26 <SEP> 8
<tb> 16 <SEP> 7 <SEP> 27 <SEP> 20 <SEP> 13 <SEP> 2
<tb> 41 <SEP> 52 <SEP> 31 <SEP> 37 <SEP> 47 <SEP> 55
<tb> 30 <SEP> 40 <SEP> 51 <SEP> 45 <SEP> 33 <SEP> 48
<tb> 44 <SEP> 49 <SEP> 39 <SEP> 56 <SEP> 34 <SEP> 53
<tb> 46 <SEP> 42 <SEP> 50 <SEP> 36 <SEP> 29 <SEP> 32
<Tb>

In a similar way to the Choice 1 Switched, the Switched Choice 2 changes the disposition status of the bits of Ci and

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 Di as shown in Table 3, thereby producing 48 key bits Ki corresponding to each offset rounding.

 Keys K i (i = 1, ..., 16) thus produced are applied to the data encryption portion 10 of the standard data encryption algorithm.

 In decryption, the above mentioned protocol is repeated in reverse order, namely from C16 and D16 to produce the keys. Here, we performed a shift to the right.

 Figure 2 shows the comparison of offset dimensions during encryption and decryption. As shown in FIG. 2, the offset dimension of C1 to C16 in the encryption is the same as the offset dimension of C16 to C1 in decryption.

 In order to implement the standard data encryption algorithm of FIG. 1 in a hardware device, an encryption block and a decryption block are individually formed. However, considering that the repeated algorithm is applied to each block, the same constituent elements in each block are used individually. As a result, a large number of components and a large space are required to implement the hardware equipment for the standard data encryption algorithm, which decreases the efficiency of the design of the hardware equipment.

 A key training device for a standard data encryption algorithm according to the preferred embodiments of the present invention will now be described in detail with reference to Figs. 3-6.

 Fig. 3 is a block diagram illustrating the structure of a hardware equipment for key formation for encryption and decryption for the standard data encryption algorithm according to a first embodiment of the present invention.

 The key-forming device comprises three pairs of multiplexers 310,312, 314,316, 318 and 320,

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 a pair of rotators 326 and 328, a pair of registers 322 and 324 and two pairs of inverse disposition units 330,332, 334 and 336, which are divided into a portion for calculating the leftmost bits Ci and a portion for calculating the bits Di right.

 According to the first embodiment of the invention, the key-forming device calculates keys by division to give Ci and Di in order to efficiently obtain the keys, and it reduces a large number of calculation elements in order to obtain the keys. optimize the structure of the equipment.

 In addition, the key formation unit comprises a key control unit 340 for receiving an initial key value K, outputting C1 and D1 during encryption, and outputting C16 and D16 during decryption, as well as a decoder unit. forming keys 338 to produce keys using the calculated Ci and Di.

 The key control unit 340 may be constituted as shown in FIG. 4. Therefore, in the encryption, a Choice 1 Switched unit 350 performs the Switched Choice 1 using 64 bits of the initial key K, and divides by 28 The 64 bit key K obtained to give CO and DO, and shifters 354 and 358 respectively deliver Cl and Di by shifting left CO and DO by 1 bit. In addition, in decryption, the key control unit 340 divides the initial key K into CO and DO after the swapped Choice 1, and delivers CO and OD respectively as C16 and D16. The multiplexers 352 and 356 deliver C1 and D1 or C16 and D16 according to an encryption decryption decision signal A.

 At this point, if C16 and C17 are produced by shifting CO and DO as shown in Figure 2, CO and DO have 28 bits and their offset dimension is 28 bits and so CO and DO have the same values as C16 and D16. CO and DO are therefore delivered as C16 and D16 during decryption.

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 As a result, when the initial key K is applied to the key control unit 340, the key control unit 340 outputs Ci and Di (Ci and Dl in the encryption, and C16 and D16 in the decryption). by performing the operations mentioned above.

 After that, the multiplexers 310 and 312 record Ci and Di from the key control unit 340 respectively on the registers 322 and 324 in accordance with a selection signal S. The registers 322 and 324 transmit to the multiplexers 314 and 316 and the reverse disposition units 330 and 332, the registered Ci and Di. The inverse disposition units 330 and 332 modify the arrangement of Ci and Di from the registers 322 and 324, and transmit them to the multiplexers 314 and 316.

 Thus, multiplexers 314 and 316 receive Ci and Di respectively from registers 322 and 324 and reverse disposition units 330 and 332. At this point, Ci and Di transmitted from registers 332 and 324 and reverse disposition units 330 and 332 have different disposition states.

 It is at this point possible to produce the deciphering encryption decision signal A, the selection signal S or an offset size control signal B which will be explained later and which are provided by a predetermined control means (no shown) to control encryption and decryption. In the case where the multiplexer 310 is designed to determine the existence / absence of signals from the key control unit 340 and the multiplexer 318 and to perform the selection operation, the selection signal S n ' does not need to be applied externally. In addition, when the rotator 326, which will be explained later, is designed for a rounding counter, the shift size control signal B does not need to be applied externally either.

 The multiplexers 314 and 316 determine to produce keys for the encryption or keys for the

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 decryption according to the decryption encryption decision signal A. The multiplexers 314 and 316 receive Ci and Di from the registers 322 and 324 to produce the keys for encryption, receive Ci and Di from the reverse disposition units 330 and 332 to produce the keys for decryption, and transmit them to the encryption keys. rotators 326 and 328.

 At this point, the rotators 326 and 328 shift Ci and Di transmitted from the multiplexers 314 and 316 in a first predetermined direction. In the case of the shift to the left, the most significant bits (BPS) of the rotators 326 and 328 are rotated to form the least significant bits (BMS) and are then applied.

 At this point, the rotators 326 and 328 control the offset dimensions of Ci and Di according to the offset dimension control signal B that is applied.

 The offset Ci and Di are transmitted to the multiplexers 318 and 320 and the reverse disposition units 334 and 336. The reverse disposition units 334 and 336 change the disposition state of Ci and Di from the rotators 326 and 328, and they transmit Ci and Di to the multiplexers 318 and 320.

 The multiplexers 318 and 320 receive Ci and Di respectively from the rotators 326 and 328 and the reverse disposition units 334 and 336. At this point, Ci and Di transmitted from the rotators 326 and 328 and the reverse disposition units 330, 322 present different states of disposition.

 After that, the multiplexers 318 and 320 determine to produce the keys for encryption or keys for decryption according to the decryption encryption decision signal A. The multiplexers 318 and 320 select Ci and Di from the rotators 326 and 328 to produce the keys for encryption, select Ci and Di from the reverse disposition units 334, 336 to produce the keys for decryption, and they

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 transmit, to the multiplexers 310 and 312, the selected Ci and Di.

 The multiplexers 310 and 312 record on the registers 332 and 334 the Ci and Di which have been transmitted, and the aforementioned protocol is repeated to calculate Ci and Di up to C16 and D16 during the encryption and to calculate C16 and D16 up to Cl and D1 during decryption.

 The key formation unit 338 performs the Choice 2 Switched using Ci and Di recorded on registers 332 and 324, thereby obtaining Ki.

 The process mentioned above will now be briefly explained. The multiplexers 314 to 320 receive Ci and Di from the registers 322 and 324 or rotators 326 and 328 during encryption according to the decryption encryption decision signal A, and receive the Ci and Di arranged in reverse order from the units. in reverse disposition 330 to 336 during decryption, thus sorting the data according to encryption and decryption.

 The rotators 326, and 328 confirm the offset dimensions regardless of the encryption or decryption, and receive the commonly used offset size control signal B because the offset dimension of C1 and D1 to C16 and D16 is the same. the shift dimension of C16 and D16 to C1 and D1 as shown in Figure 2.

 Further, the inverse disposition units 330 to 336 are formed so that rotators 326 and 328 that shift Ci and Di in a first direction can be used in common for encryption and decryption. As a result, encryption and decryption can be implemented in the same hardware equipment.

 Furthermore, the key-forming device can be modified as shown in FIG. 5. A second embodiment of FIG. 5 modifies the rotators 326 and 328 of the first embodiment of FIG.

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 as described above. The key-forming device of FIG. 5 has the same structure as the key-forming device of FIG. 3, except that the rotators 326 and 326 comprise built-in counters (not shown) for shifting Ci and Di in each rounded according to a necessary offset dimension. Therefore, the shift size control signal B need not be applied externally, differently from FIG. 3.

 The keying device for the standard data encryption algorithm can also be implemented as shown in FIG. 6.

 As illustrated in FIG. 6, the key-forming device comprises a pair of multiplexers 410 and 420, a pair of registers 430 and 440, and a pair of rotators 450 and 460. In a manner identical to the first embodiment described below, above, the key-forming device is divided into a part to calculate Ci and a part to calculate Di in order to increase the efficiency in the calculation and to reduce the load of the structure of the equipment equipment.

 The key-forming device further comprises a key control unit 480 for receiving an initial key value K, outputting Cl and D1 during encryption, and outputting C16 and D16 during decryption, as well as a key-forming unit. 470 to produce keys using the calculated Ci and Di.

 In the encryption, the key control unit 480 performs the Choice 1 Switched using the initial key K, divides the key K obtained in CO and DO, shifts to the left CO and DO of 1 bit and delivers C1 and D1. In decryption, the key control unit 480 divides the key K obtained in CO and DO after the swapped Choice 1, and outputs them as C16 and D16. The respective operations for encryption and decryption are determined in accordance with a deciphering encryption decision signal A.

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 At this point, if C16 and D16 are produced by shifting CO and DO as shown in Figure 2, CO and DO have 23 bits and their offset dimension is 28 bits, and so CO and DO have the same values as the C16 and D16. As a result, CO and DO are delivered as C16 and D16 during decryption.

 On the other hand, the key formation unit 470 performs the Switched Choice 2 using the calculated Ci and Di, thereby producing keys.

 When the initial key K for generating the keys for encryption and decryption is applied to the key control unit 480, the key control unit 480 outputs Ci and Di (Ci and Dl in the encryption, and C16 and D16 in decryption) by performing the operations mentioned above.

 After that, the multiplexers 410 and 420 respectively record on the registers 430 and 440 the transmitted Ci and Di, and the rotators 450 and 460 respectively receive Ci and Di recorded on the registers 430 and 440.

 The rotators 450 and 460 shift left Ci and Di during encryption, and shifts right Ci and Di during decryption. At this point, the BPS and BMS are rotated and are respectively applied as BMS and BPS.

 Thus, the rotators 450 and 460 can perform a bidirectional shift, and the offset direction is determined according to the encryption and decryption.

 The decision of encryption and decryption of the rotators 450 and 460 and the resulting offset dimensions are determined in accordance with the deciphering encryption decision signal A and the shift dimension control signal B as signals for controlling the training device. keys in the embodiment of the hardware equipment structure of the standard data encryption algorithm.

 Thus, the rotators 450 and 460 determine an offset direction in accordance with the decision signal

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 A decryption encryption and the number of offset bits according to the shift dimension control signal B, and shift Ci and Di from the registers 430 and 440 in the offset direction using an internal counter or an external counter (no represented).

 The shifted values are applied to multiplexers 410 and 420, and the process described above is repeated to calculate C1 and D1 through C16 and D16 during encryption and to calculate C16 and D16 at C1 and D1 during decryption.

 At this point, the key forming device 470 performs the Choice 2 Switched using Ci and Di recorded on registers 430 and 440, thereby obtaining K i.

 According to a third embodiment according to FIG. 6, the rotators 450 and 460 comprise counters for differently using the shift dimension control signal B.

 As stated above, according to the present invention, the key-forming device for the standard data encryption algorithm optimizes the hardware equipment structure by extracting common offset points from the standard data encryption algorithm. in encryption and decryption. A unidirectional offset or bi-directional offset is used in common during encryption and decryption, optimizing the area of the hardware equipment structure.

 The invention is not limited to the exemplary embodiments shown and described in detail since various modifications can be made without departing from its scope.

Claims (8)

A key training device for a standard data encryption algorithm comprising: a key control unit for producing a rising data and a descendant data by performing operations for encryption and decryption by using a key value initial ; a first shift unit for shifting the ascending data in a first direction; a second shift unit for shifting the descending data in the first direction; and a key training unit for generating keys for encryption and decryption for the standard data encryption algorithm by performing a Switched Choice 2 of the standard data encryption algorithm by using the shifted data in the data encryption algorithm. first shift unit and the second shift unit, characterized in that each of the first and second shift units comprises: a register; a first multiplexer for selectively transmitting to the register either the upstream data or the downlink data and a feedback data; a first inverse disposition unit for reverse arranging the register data; a second multiplexer for transmitting the register data during encryption and transmitting the data of the first reverse disposition unit during decryption; a rotator for shifting the data of the second multiplexer in a first direction in bit units; a second inverse disposition unit for reverse arranging the rotator data; and a third multiplexer for transmitting to the first multiplexer the rotator data as <Desc / Clms Page number 15>  feedback data during encryption, and transmitting to the first multiplexer the data of the second reverse layout unit as feedback data during decryption.  2. Device according to claim 1, characterized in that the key control unit performs a Choice 1 Switched from the standard data encryption algorithm using the initial key value, divides the key value obtained into a given data. initial upstream and downstream data, produces the upstream data and the downward data by shifting the initial upstream data and the initial 1-bit downward data to the left during the encryption, and produces the initial upstream data and the initial downward as rising data and descending data during decryption.  3. Device according to claim 1, characterized in that the key control unit, the second multiplexer and the third multiplexer determine the encryption and decryption according to an encryption decision signal decryption of the standard encryption algorithm. data.  4. Device according to claim 1, characterized in that the rotator uses either the iriterne counter or the external counter, and determines an offset dimension and processes it according to an offset dimension control signal of the standard data algorithm. .  A key training device for a standard data encryption algorithm, comprising: a key control unit for producing a rising data and a descendant data by performing operations for encryption and decryption by the use of a data encryption value; initial key; a first shift unit for shifting up data; a second shift unit for shifting the descending data; and <Desc / Clms Page number 16>  a key training unit for generating keys for encryption and decryption for the standard data encryption algorithm by performing a Choice 2 Swapped of the standard data encryption algorithm by using the shifted data in the first shift unit and the second shift unit, characterized in that each of the first and second shift units comprises: a register; a multiplexer for selectively transmitting to the register either the rising data or the falling data and a feedback data; and a rotator for shifting the register data in a first bit unit direction during encryption and decryption, and transmitting the resulting data to the multiplexer as feedback data.  6. Device according to claim 5, characterized in that the key control unit performs a Choice 1 Switched from the standard data encryption algorithm using the initial key value, divides the key value obtained into a given data. initial up-and-down data, and outputting data and descending data by shifting the initial upstream data and the initial 1-bit downward data to the left during encryption, and outputting the initial upstream data and the initial downward data as as rising data and descending data during decryption.  Device according to claim 5, characterized in that the rotator uses an internal counter or an external counter, determines an offset dimension in accordance with an offset dimension control signal of the standard data encryption algorithm, shifts to left the data during encryption, and shifts the data right during decryption.  8. Device according to claim 5, characterized in that the key control unit and the rotator <Desc / Clms Page number 17>  determine the encryption and decryption according to an encryption decision signal decryption of the standard data encryption algorithm.