TW201337633A - System, devices and methods for collaborative execution of a software application comprising at least one encrypted instruction - Google Patents

Abstract

Collaborative execution by a first device (110) and a second device (120) of a software application comprising at least one encrypted instruction (J). The first device (110) obtains (S10) a first encrypted instruction (J); generates (S11; S20) a session key k2; encrypts (S11; S21) the first encrypted instruction (J); encrypts (S11; S22) the session key k2 using a symmetric algorithm and a first key k1; and transfers (S12; S23) the encrypted first encrypted instruction and the encrypted session key k2 to the second device (220). The second device (220) decrypts (S13; S24) the encrypted session key k2 using the first key k1; decrypts (S13; S25) the encrypted first encrypted instruction to obtain the first encrypted instruction (J); decrypts (S14; S26) the first encrypted instruction using a third key kpre to obtain an instruction (I); encrypts (S15; S27) the instruction (I) using the symmetric encryption algorithm and the session key k2 to obtain a second encrypted instruction (M); and transfers (S15; S28) the second encrypted instruction (M) to the first device (210). The first device (210) decrypts (S17; S29) the second encrypted instruction (M) using the session key k2 to obtain the instruction (I); and executes (S18; S30) the instruction (I).

Description

First method and first device and second method and second device participating in co-executing software application

The present invention relates generally to encryption, and more particularly to security protocols for common processing.

This section is intended to introduce the reader to the technical aspects and may be related to the gist of the invention described below and/or in the scope of the claims. This discussion helps to provide readers with background information to better understand the gist of the present invention. Therefore, it is to be understood that such statements are read here rather than incorporated into the prior art.

The known security issue is how to ensure the application of the software. The original software application is not supported, and the software application cannot be properly executed.

Typical prior art protection, including support for software applications being tied to distribution. The binding mechanism is generally based on information specific to support (support ID, support keywords, etc.). However, there are still shortcomings, especially when the application is designed to operate on a non-credit platform.

Therefore, it is necessary to have an agreement that, when co-processing certain shared data, causes the first device to check the existence of the second device, that is, the agreement ensures that, for example, a computer that operates an application is required for proper execution of the application. The dongle exists.

WO 2009/095493 describes the following agreement to verify the existence of small devices:

1. The software vendor uses algorithms and only keywords known to the software vendor to pre-encrypt at least some of the instructions of the software application, ie J=E _pre {k _pre }(I). Then, copy the encryption software application to its distribution support.

2. Corresponding to the decryption module E _pre ^-1 and the keyword k _pre , the circuit is known for welding on the distribution support, but the software application is unknown. Therefore, the instruction J=E _pre {k _pre }(I) cannot be decrypted by the application running on the host, and if executed as such, it may result in an incorrect error operation.

3. The application sends the data to the support, and the circuit is used each time the protection command J needs to be executed.

This agreement is interesting, but it still has value for dictionary intrusion. This is especially true if the intruder can detect the communication bus of the host and the distribution support machine.

A possible alternative is to use the standard public keyword cryptography mechanism. For example, a channel for secure authentication can be set up between the game console and the circuit to prevent any communication spies. However, this will greatly increase the cost of the circuit, because it is necessary to implement the public keyword cryptography algorithm safely and effectively. In particular, the use of public keyword cryptography prevents the implementation of hardware only.

A solution between the two is found in WO 2005/064433, in which the computer uses the common keywords of the block, procure the encrypted static data, generate random values, encrypt using public keywords, encrypt the static data and randomize Value, sent to the block. The block uses its private keyword to decrypt these items, uses the random value as the encryption key, encrypts the static data, sends the re-encrypted static data back to the computer, decrypts the static data and uses it. Although the solution works well, it is quite resource-intensive because it uses asymmetric encryption and encrypts static data specifically for each block.

Therefore, there is a need for a solution that overcomes the shortcomings of the prior art. The present invention provides such a solution.

The first aspect of the present invention is directed to a first method of participating in a common execution of a software application, the software application comprising at least one encryption instruction, which is an encryption of an unencrypted instruction. The first device obtains the first encryption instruction; generates a trial keyword; encrypts the trial keyword using the symmetric encryption algorithm and the first keyword; and transfers the first encryption command and the encrypted trial keyword to the second device; The second device receives the second encryption instruction, the second encryption instruction is the unencrypted instruction using the trial keyword encryption; the second encryption instruction uses the symmetric encryption algorithm and the trial keyword decryption to obtain the unencrypted instruction; and executes the unencrypted instruction.

In the first preferred embodiment, the first device super-encrypts the first encryption command before transferring to the second device.

A second aspect of the present invention is directed to a second method of participating in a co-executing software application, the software application including at least one encryption instruction. The second device receives the first encryption instruction and the encryption trial keyword from the first device, the trial keyword uses a symmetric encryption algorithm and the first keyword encryption; uses the first keyword to decrypt the encryption trial keyword; the first encryption instruction Use symmetric encryption The algorithm and the third keyword are decrypted to obtain an instruction; the instruction uses a symmetric encryption algorithm and a trial keyword encryption to obtain a second encryption instruction; and the second encryption instruction is transferred to the first device.

In a first preferred embodiment, the received first encrypted command is over-encrypted, and the second command further decrypts the encrypted first encrypted command.

A third aspect of the present invention is directed to a first device constituting a co-executing software application, the software application including at least one encryption instruction, which is an encryption of an unencrypted instruction. The first device comprises a processor, configured to: obtain a first encryption instruction, generate a trial keyword; use a symmetric encryption algorithm and a first keyword to encrypt the trial keyword; and transfer the first encryption command and the encrypted trial keyword to the first The second device receives a second encryption instruction from the second device, the second encryption instruction is an unencrypted instruction using a trial keyword encryption; the second encryption instruction uses a symmetric encryption algorithm and a trial keyword decryption to obtain an instruction; and executes the instruction.

In the first preferred embodiment, the processor is configured to super-encrypt the first encrypted command before transferring to the second device.

A fourth aspect of the present invention is directed to a second device constituting a co-executing software application, the software application including at least one encryption instruction. The second device comprises a processor, configured to: receive the first encryption instruction and the encryption trial keyword from the first device, the trial keyword uses a symmetric encryption algorithm and the first keyword encryption; and the encrypted trial keyword uses the first keyword to decrypt The first encryption instruction uses a symmetric encryption algorithm and a third keyword decryption to obtain an instruction; the instruction uses a symmetric encryption algorithm and a trial keyword encryption to obtain a second encryption instruction; and transfers the second encryption instruction to the first device .

In a first preferred embodiment, the processor constitutes a first encrypted instruction that receives the super-encryption, and decrypts the encrypted first encrypted instruction by a super-encryption to obtain a first encrypted instruction.

110‧‧‧Host

120‧‧‧ Circuitry

200‧‧‧ system

210‧‧‧Host

211‧‧‧ROM

212‧‧‧RAM

213‧‧‧ processor

214‧‧‧ interface

215‧‧‧Software applications

220‧‧‧Auxiliary devices

221‧‧‧ interface

222‧‧‧ Block cipher circuit

223‧‧‧ non-argumental memory

2111‧‧‧This family of software

2131‧‧‧ Core CPU

2132‧‧‧CPU hidden device

2133‧‧‧CPU register

2151‧‧‧block password

2152‧‧‧Encryption instructions

S10‧‧‧Read pre-encrypted instruction J

S11‧‧‧L by using the keyword k _{1 to} encrypt J and random k ₂

S12‧‧‧ sends the first transfer value L to the circuit 120

S13‧‧‧Use k _{1 to} decrypt L and get J and k ₂

S14‧‧‧Decrypted J and got I

S15‧‧‧M=Encryption with k ₂

S16‧‧‧ sends the second transfer value M to the host 110

S17‧‧‧ Use k _{2 to} decrypt M and get I

S18‧‧‧Execution Directive I

S20‧‧‧ generates random k ₂

S21‧‧‧XORs k ₂ and J have the first transfer value L ₁ =J ♁ k ₂

S22‧‧‧ encrypting the random second transfer value L ₂ =E ₁ {k ₁ }(k ₂ ) using the first bus encryption module E ₁ and the keyword k ₁

S23‧‧‧ sends a first transfer value and a second transfer value pair (L ₁ , L ₂ ) to the circuit 120

S24‧‧‧ Decrypt L ₂ to random k ₂ using the first bus decryption modules D ₁ and k ₁

S25‧‧‧calculated J=L ₁ ♁ k ₂

S26‧‧‧Use the third decryption module D _pre and the third keyword k _pre to decrypt J to obtain the instruction I

S27‧‧‧ Calculate the XOR between instruction I and k ₂ to obtain the third transfer value M=I ♁ k ₂

S28‧‧‧ sends the third transfer value M to the host

S29‧‧‧ Calculate I=M ♁ k ₂ Get the instruction I cleared

S30‧‧‧Execution Directive I

1 is a schematic diagram of a method for executing a software application according to a preferred embodiment of the present invention; FIG. 3 is a diagram showing a preferred embodiment of the present invention for performing a software application; 4 is a block diagram of a processor of a preferred embodiment of the present invention; and FIG. 5 is a block diagram of a block cipher circuit of a preferred embodiment of the present invention.

Preferred features of the invention are described with reference to the non-limiting embodiments illustrated in the drawings.

The main idea of the invention is to use a life protection mechanism to engage the pre-encryption mechanism.

In other words, the protection mechanism is used to protect the bus at the time of data transfer. The data bus protection mechanism implemented by the host is designed such that unprotected operations (also partially performed by the host) are only effective in the presence of the circuit, preferably in conjunction with distribution support. To this end, a partial protection mechanism is shared between the host and the hardware modules implemented by the circuit, that is, the circuit includes a decryption method unknown to the software application. The proposed protection practice is effective in terms of efficiency and hardware/software implementation.

A software application intended to be executed by a host CPU includes a first bus cryptographic module E ₁ and a (preferably symmetric) keyword k ₁ and a second bus decryption module D ₂ . The software application also includes at least one encrypted (or even pre-encrypted) instruction J that needs to be decrypted prior to execution. The distribution support for the storage software application, including the circuit, has the first bus decryption module D ₁ and the keyword k ₁ , which is equivalent to the first bus encryption module (ie, the symmetric encryption case is consistent, and in the asymmetric encryption case) At the time, it is the "other" keyword of the pair of keywords), and the second bus encryption module E ₂ . The circuit further includes a third decryption module _Dpre , and a fixed third keyword _kpre ; these enable decryption of the pre-encryption. It should be noted that at least one encryption command J has been encrypted by the software provider using the encrypted keyword equivalent to the third keyword k _pre before the software application is distributed; preferably, the software provider can encrypt and decrypt, and the current can only be decrypted. .

The keyword k ₁ should be reserved first and shared by the circuit and the host. It is best to mix in the software application to be executed by the host CPU. It is also preferable for the host and the circuit to perform the encryption algorithm in a single "direction", that is, encryption or decryption, and the "direction" of the host and the circuit are different.

Figure 1 is a diagram showing a generalized method of executing a software application of the present invention. When the software application is to execute the encryption instruction J, the host CPU 110 (execution software application): a. reads the S10 encryption instruction J; b. uses the first bus encryption module E ₁ and the keyword k ₁ to encrypt the S11 random k2 In combination with the encryption command J, a first transfer value L is obtained, that is, L = E ₁ {k ₁ } (J ∥ k ₂ ); c. The first transfer value L of S12 is transmitted to the circuit 120.

When receiving the first transfer value L, the circuit 120: d. uses the first bus decryption module D ₁ and the keyword k ₁ , decrypts L to S13, obtains random k ₂ and encrypts the command J; e. uses the third decryption Module D _pre and third keyword k _pre , decrypt J to S14 to obtain instruction I; f. use second bus encryption module E ₂ and random k ₂ (with keyword action) to encrypt instruction S1, A second transfer value M is obtained, that is, M=E ₂ {k ₂ }(I); g. The S16 second transfer value M is transmitted to the host 110.

Finally, since the software application knows k ₂ and includes the bus decryption module D ₂ , the instruction J in the S17 clear can be obtained by calculating I=D ₂ {k ₂ }(M), and then the host can execute the S18 command. I.

It can be seen that the random k ₂ can be said to have the role of the instruction hearing keyword, both of which are in their encrypted form and their re-encrypted form. It can be seen that the generalization method does not require super-encryption of the encryption instruction J, in which case it is sent in the clear (preferably together with the encrypted random k ₂ ), that is to say the decryption in the step d, only the random k ₂ is provided.

The protocol of the present invention can greatly improve security because encryption is based on fresh randomness generated during each iteration, meaning that replay intrusion is blocked.

Since the host application environment is not trusted, the first encryption operation of the software application is preferably implemented in a white box, and the keyword k _{1 is} obtained from the code. It is best that k _{2 is} also protected in this way to prevent the opponent from checking at a reasonable cost. The measures include, for example, using a hardware random number generator on the chip to generate a new keyword value for the CPU (at boot time) and store it in the anti-chaos keyword register.

A preferred protection for software applications is the use of regular usage agreements, such as borrowing multiple protected instructions, while the software application is executing.

Moreover, whenever the host does not use an external current, it is preferable to generate a random simulation access in order to make the bus bar observation analysis complicated.

First preferred embodiment

FIG. 2 is a diagram showing an example of a method for executing a software application according to the present invention. The software application includes at least one cryptographic software instruction, such as located within a particular address or data segment of the software code. When the software application is to execute the encryption instruction J, the host CPU 110 is executing the software application: a. generating S20 random k ₂ ; b. XORs k ₂ and J, obtaining the first transfer value; L ₁ = J ♁ k ₂ , step S21 c. Using the first bus encryption module E ₁ and the keyword k ₁ , the encryption S22 is random, and the second transfer value is obtained, that is, L ₂ = E ₁ {k ₁ }(k ₂ ); d. The transfer value and the second transfer value are paired (L ₁ , L ₂ ) to the circuit 120.

When receiving a pair of transfer values (L ₁ , L ₂ ), the circuit 120: e. uses the first bus decryption module D ₁ and k ₁ , decrypts L ₂ to S 24 to obtain a random k ₂ ; f. calculates S25, J=L ₁ ♁ k ₂ ;g. Using the third decryption module D _pre and the third keyword k _pre , decrypting J S26 to obtain the instruction I; h. calculating the XOR between the S27 instruction I and k ₂ The triple transfer value M, M = I ♁ k ₂ ; i. Send the S28 third transfer value M to the host.

Finally, since the application knows, the instruction I in the S29 clear can be obtained by computing I=M ♁ k ₂ , and then the host can execute the S30 instruction I.

In the specific example of the change, the encryption command J is sent from the host to the circuit during the clearing, that is, L ₁ = J, then steps b and f are not performed.

FIG. 3 is a diagram showing a preferred embodiment of the present invention for jointly executing a software application system. This system 200 includes a host 210 and an auxiliary device 220.

The host 210 can be virtually any type of processing device, preferably a personal computer and a game console. The host 210 preferably includes a ROM 211, a RAM 212, at least one processor 213, and an interface 214 adapted to interact with the auxiliary device 220. The ROM 211 stores the family of software 2111, while the RAM 212 stores the software application 215 (which should be downloaded from the auxiliary device 220), including the white box implementation block code 2151 (such as AES), and a number of encryption instructions 2152. The processor 213 is adapted to execute the native software 2111 and the software application 215.

The auxiliary device 220 is preferably an RFID, and includes an interface 221 for communicating with the host 210, a processor (block cipher circuit) 222 for accessing at least the above two keywords k ₁ and k _pre , and a non-aliasable memory 223. It should be noted that the auxiliary device 220 can also implement two different block passwords, one for each keyword. The block cipher circuit 222 is functionally coupled to the interface 221 and the non-aliasable memory 223.

During execution, the software application 215 can store data in the non-aliasable memory 223, or thereby remedy the data.

As shown in FIG. 4, the host CPU 213 includes a core CPU 2131 to execute software. The data bus protection function is recorded in the CPU buffer 2132, generating a random k ₂ ; encrypting k ₂ and J using E ₁ and transmitting the encryption to the interface 214. The data bus decryption function is recorded in the CPU register 2133, receives k ₂ from the CPU buffer 2132, and receives the encrypted command M=k ₂ ♁ I from the interface 214, and then obtains the clear by calculating I=k ₂ ♁ M In the instruction I, then the core CPU 2131 can execute the instruction 1.

At least one instruction is encrypted before the software application is distributed. It is best to use the chance plus The secret is reached so that under the same keyword, there are two different encryptions for the same input.

The software application can be delivered to host 210 using any suitable dispensing mechanism (e.g., internet, optical media, or within auxiliary device 220). In the case of software applications distributed through the Internet, the auxiliary device 220 must try to deliver to the user of the software application and operate properly.

Software application preferably comprises a white-box implementation of a private keyword of k AES _decryption module. Software applications also contain a collection of encrypted instructions.

Second preferred embodiment

Here, the instruction XORs each instruction I _i with an encrypted random value E(R _i ), that is, I _i ♁ E(R _i ). The encryption instruction is stored along with the corresponding random value, and is given a subset of the encryption instruction: {(I ₀ ♁ E(R ₀ ); R ₀ );...

(I _i ♁ E(R _i ); R _i );...

(I _n ♁ E(R _n ); R _n )}

The host protocol can be implemented as follows, assuming that the instruction I is 64 bits long, and the random values R _i , k ₂ and k _{3 are} also 64 bits long, and the algorithms E ₁ and E _pre are 128 bits implemented in the ECB mode. Meta AES encryption. Under the keyword k ₁ E ₁ lines in white-box implementation, the encryption algorithm E ₂ (and a decryption algorithm D _2), using a two-based random value k ₂ and k _3, to implement an XOR operation.

The corresponding auxiliary device agreement is implemented as follows:

It can be seen that the agreement partially coincides, even if the variable names are different; this reflects, for example, that k ₂ and k' _{2 are} identical when the agreement is supposed to work, but the auxiliary device has no way of knowing whether this is the case (the same is shown in Figure 5 below).

For the auxiliary device, it is assumed that the non-aliasing memory 223 is easily readable by the host, but the block cipher circuit 223 is confusing. Figure 5 is a block diagram showing a block cipher circuit of a second embodiment of the present invention.

The AES implementation described by Menezes, van Oorschot and Vanstone is a wafer with 3,595 gates. Encrypting 128 bits takes about 1000 cycles. Since a two-encryption step is required in the agreement, specifying a field requires approximately 2000 hours to process the data.

It will thus be appreciated that the present invention provides a lightweight agreement to authenticate and verify the presence of an auxiliary device.

From a benefit perspective, the benefits include: • The minimum number of exchanges and their content. In terms of 64-bit instructions and AES block ciphers, the number of bytes exchanged is 32 bytes (L ₁ +L ₂ +M); ‧ only two transfers in the agreement; ‧ computational complexity on both sides Both are low: the host has 1 block encryption, and the auxiliary device has 2 block encryption.

From a security point of view:

‧ The agreement can be updated due to different agreement keywords and white box implementations between software applications.

‧ More importantly, the agreement is safe, because it can be used against the replay and intruders in the dictionary of the secret search bus at the time of data transfer.

‧The agreement can provide preferential price/security transactions and can be used to protect current applications.

Although the above encryption instructions facilitate reading from distribution support, such as DVD or CD-ROM, it can also be read from external sources such as servers or the Internet. Moreover, in the specification, the encryption instructions are encrypted using a generalized encryption method, including, for example, normal encryption (such as used to protect the trial keyword k ₂ ) and confusion (eg, using an arrangement of the operation codes), and the keyword is equivalent to how to recover The "instructions" of chaos.

The specification and, where appropriate, the scope of the patent application and the features disclosed in the drawings may be provided separately or in any suitable manner. The features are implemented by hardware or by software, and vice versa. The reference numbers appearing within the scope of patent application are for reference only and have no limitation on the scope of patent application.

110‧‧‧Host

120‧‧‧ Circuitry

S10‧‧‧Read pre-encrypted instruction J

S11‧‧‧L by using the keyword k _{1 to} encrypt J and random k ₂

S12‧‧‧ sends the first transfer value L to the circuit 120

S13‧‧‧Use k _{1 to} decrypt L and get J and k ₂

S14‧‧‧Decrypted J and got I

S15‧‧‧M=Encryption with k ₂

S16‧‧‧ sends the second transfer value M to the host 110

S17‧‧‧ Use k _{2 to} decrypt M and get I

S18‧‧‧Execution Directive I

Claims (8)

A first method for participating in a common execution software application, the software application comprising at least one encryption instruction (J) being an encryption of an unencrypted instruction (I), the method comprising the steps in the first device (210): obtaining (S10) the first Encryption instruction (J); generating (S11; S20) trial keyword k ₂ ; using symmetric encryption algorithm and first keyword k ₁ , encrypting (S11; S22) hearing keyword k ₂ ; And encrypting the challenge keyword k ₂ , transferring (S12; S23) to the second device (220); receiving (S16; S28) the second encryption command (M) from the second device (220), the second encryption command (M) The unencrypted instruction (I) is encrypted using the trial keyword k ₂ ; the symmetric encryption algorithm and the trial keyword k _{2 are used} to decrypt (S17; S29) the second encrypted instruction (M), resulting in an unencrypted instruction (I); Execute (S18; S30) the unencrypted instruction (I). The first method of participating in the software application, as in the first application of the patent scope, further includes a super-encrypted first encryption instruction (J), wherein the first encryption instruction is transferred to the second device (220) by super-encryption. A second method of participating in a common execution of a software application, the software application comprising at least one encryption instruction (J), the method comprising the step of: receiving, at the second device (210), the first device (210) (S12; S23) The encryption instruction and the encryption trial keyword k ₂ , the trial keyword k ₂ is encrypted using the symmetric encryption algorithm and the first keyword k ₁ ; using the first keyword k ₁ , decrypting (S13; S24) encrypting the trial keyword k ₂ Using the symmetric encryption algorithm and the third keyword k _pre , decrypting (S14; S26) the first encryption instruction, obtaining the instruction (I); using the symmetric encryption algorithm and the trial keyword k ₂ , decrypting (S15; S27) instructions (I), obtaining a second encryption command (M); transferring the second encryption command (M) (S15; S28) to the first device (210). The second method of participating in the software application, as in the third aspect of the patent application, wherein the first encryption instruction is received by hyper-encryption, and wherein the second device further encrypts the encrypted first encryption instruction and decrypts it. A first device (210) participating in a co-executing software application, the software application comprising at least one encryption instruction (J), which is an encryption of an unencrypted instruction (I), the first device (210) comprising a processor (213), constituting : obtaining a first encrypted instruction (J); generating trial keyword k _2; symmetric encryption algorithm using a first keyword and k _1, encryption trial keyword k _2; the first encrypted instruction (J) and Image encryption trial k ₂ , transferring to the second device (120); receiving a second encryption instruction (M) from the second device (120), the second encryption instruction (M) being an unencrypted instruction (I) using the trial keyword k _{2 to} encrypt; The symmetric encryption algorithm and the trial keyword k _{2 are used} to decrypt the second encrypted instruction (M) to obtain the instruction (I); and the instruction (I) is executed. For example, the first device of claim 5 of the patent scope further constitutes a super-encrypted first encryption command (J), and wherein the first encryption command (J) is transferred to the second device by super-encryption. A second device (220) participating in a co-executing software application, the software application comprising at least one encryption instruction (J), the second device (220) comprising a processor (222) configured to receive the first device (110) An encryption instruction and an encryption trial keyword k ₂ , the trial keyword k ₂ is encrypted using a symmetric encryption algorithm and a first keyword k ₁ ; the first keyword k _{1 is used} to decrypt the encrypted trial keyword k ₂ ; The algorithm and the third keyword k _pre , decrypt the first encryption instruction, obtain the instruction (I); use the symmetric encryption algorithm and the trial keyword k2, decrypt the instruction (I), obtain the second encryption instruction (M); The second encryption instruction (M) is transferred to the first device (110). The second device of claim 7, wherein the processor is configured to receive the super-encrypted first encryption instruction, and super-encrypt and encrypt the encrypted first encryption instruction to obtain the first encryption instruction (J) By.