https://elvis.hcw.ac.at/wiki/api.php?action=feedcontributions&feedformat=atom&user=LCislo 2026-09-10T16:27:16Z User contributions MediaWiki 1.41.5 https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2471 2020-01-14T16:57:04Z

<p>LCislo: /* References */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> *1) The sender sends his serial number in plaintext to the receiver<br /> *2) The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> *3) The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last counted counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used.<br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip or analyze the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * microchip. Keeloq R decryption routines in c tb041. microchip.https://www.microchip.com<br /> * Nicolas T. Courtois, Gregory V. Bard, and David Wagner. Algebraic and slide attacks on keeloq. In Kaisa Nyberg, editor, Fast Software Encryption, pages 97{115, Berlin, Heidelberg, 2008. Springer Berlin Heidelberg.<br /> * Thomas Eisenbarth, Timo Kasper, Amir Moradi, Christof Paar, Mahmoud Salmasizadeh, and Mohammad T. Manzuri Shalmani. On the power of power analysis in the real world: A complete break of the keeloq code hopping scheme. In David Wagner, editor, dvances in Cryptology { CRYPTO 2008, pages 203{220, Berlin, Heidelberg, 2008. Springer Berlin Heidelberg.<br /> *Sebastiaan Indesteege, Nathan Keller, Orr Dunkelman, Eli Biham, and Bart Preneel. A practical attack on keeloq. In Nigel Smart, editor, Advances in Cryptology { EUROCRYPT 2008, pages 1{18, Berlin, Heidelberg, 2008. Springer Berlin Heidelberg<br /> * C. Paar, T. Eisenbarth, M. Kasper, T. Kasper, and A. Moradi. Keeloq and side-channel analysis-evolution of an attack. In 2009 Workshop on Fault Diagnosis and Tolerance in Cryptography (FDTC), pages 65{69, Sep. 2009.<br /> * Orr Dunkelman Eli Biham Sebastiaan Indesteege, Nathan Keller and Bart Preneel. A practical attack on keeloq. Computer Science Department, Technion. Haifa 32000, Israel, 8(1):1{18, Oktober 2008.<br /> * Christof Paar Thomas Eisenbarth, Timo Kasper. Sicherheit moderner funkturo�nersysteme. Datenschutz und Datensicherheit, 28(1):508{510, Oktober 2008. <br /> * Nicolas T. CourtoisGregory V. BardDavid Wagner. Algebraic and Slide Attacks on KeeLoq. International Workshop on Fast Software Encryption. Springer-Verlag Berlin Heidelberg 2008, 2008.<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2470 2020-01-14T16:46:08Z

<p>LCislo: /* KeeloQ */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> *1) The sender sends his serial number in plaintext to the receiver<br /> *2) The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> *3) The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last counted counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used.<br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip or analyze the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2469 2020-01-14T16:37:51Z

<p>LCislo: /* Security Threats */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> *1) The sender sends his serial number in plaintext to the receiver<br /> *2) The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> *3) The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last received counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used.<br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip or analyze the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2468 2020-01-14T16:28:30Z

<p>LCislo: /* Description */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> *1) The sender sends his serial number in plaintext to the receiver<br /> *2) The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> *3) The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last received counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used.<br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip through analyzing the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2467 2020-01-14T16:27:30Z

<p>LCislo: /* Description */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> 1) The sender sends his serial number in plaintext to the receiver<br /> 2) The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> 3) The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last received counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used.<br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip through analyzing the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2466 2020-01-14T16:15:56Z

<p>LCislo: /* KeeloQ */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> 1. The sender sends his serial number in plaintext to the receiver<br /> 2. The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> 3. The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last received counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used.<br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip through analyzing the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2465 2020-01-14T16:15:07Z

<p>LCislo: /* Description */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Microchip Technology Inc. The system consists of a sender and a receiver, like a car remote key and a car. In order to get access with the remote key, the receiver must first learn about the remote key. To perform the registration process, the sender has a unique serial number and secret key and the receiver has a secret manufacturer key. This process can be described as followed:<br /> <br /> 1) The sender sends his serial number in plaintext to the receiver<br /> 2) The receiver’s secret manufacturer key will then be used for the encryption of the serial number. <br /> 3) The decrypt the message, the sender’s secret key works as a pair to the manufacturer key. From this point on, the sender’s key is used to encrypt and decrypt the messages. <br /> <br /> Encrypted 32-bit blocks are used for communication. Each block contains a code for a specific action. As these codes remain unchanged during a communication, every encrypted message would technically be identical. To prevent this behavior, the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the receiver decrypts a message, the counter is read. If the received counter, is a number within a range of 16 values difference from the last received counter, the action is executed.<br /> <br /> To ensure that the received message is from the same remote key and is not a resent message from someone else, the friend or foe algorithm is used. This algorithm is a challenge response algorithm. To verify the remote key, the receiver first sends a message in plaintext to the sender. The sender encrypts the message and sends it back. If the receiver can successfully decrypt the message, the remote key is verified. <br /> <br /> KeeloQ is a block cipher that uses 64-bit keys on 32-bit plaintext blocks. To encrypt messages, KeeloQ uses a 64-bit long secret key on a 32-bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate a single bit with a nonlinear function. To create a single bit for an encrypted message, a nonlinear function is applied, that XORs with one bit from the key, and two bits from the plaintext register. After that, the plaintext register, and the key register are shifted one bit to the right. This process is repeated 527 more times to create one block of an encrypted message. To decrypt a message a similar routine is used. <br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack, a side channel is used to obtain the secret sender key. This side channel can be applied on the entirety of the hardware. Some side channel attacks measure the current consumption of a semiconductor chip through analyzing the emitting electromagnetic field.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the block cipher, that is the 528 cycles long process to decrypt or encrypt a message. With enough slide pairs, which is essentially plaintext and the matching encrypted text, the steps to get the encrypted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approach the attacker tries to solve multivariate equations. These equations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2462 2020-01-12T14:56:55Z

<p>LCislo: /* References */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Micochip Technology Inc.. The system consists of a sender e.g. car remote key and a reciever e.g. car. In order to get access with a remote key, the reciever must learn about the remote key. For the regostration the remote key has a serial number and a secret key and the reciever has an secret manufacturer key. The registration process can be described as followed:<br /> <br /> 1) The sender send his serial number in plaintext to the reciever<br /> 2) The reciever has a secret manufacturer key. This key is used for the decryption of the serialnumber. <br /> 3) The solution to this decryption is the secret key of the sender. From this point the sender key is used to encrypt and decrypt the messages. <br /> <br /> To communicate blocks of 32bit are encrypted. One block contain a code for an action. This codes are always the same, therefore the encrypted messages would be always the same. To prevent this behavior the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the reciever decrypts the message the counter is read. If the recieved counter is a number within a range of 16 values difference from the last recieved counter the action is executed.<br /> <br /> To ensure that the recieved message is from the same remote key and not just a resent message from someone else the friend or foe algorithm is used. This is algorithm is an challange response algorithm. To verify the remote key the reciver sends a message in plaintext to the sender. The sender encrypts the message and send it back. If the reciever can decrypt the message correctly the remote key is verifyed. <br /> <br /> KeeloQ is an blockcipher that uses 64 bit keys on 32bit plaintext blocks. To encrypt the messages KeeloQ uses a 64bit long secret key on a 32bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate one bit with a non linear function. To get one bit from the encrypted message the solution form the non linear function is XORed with one bit from the key and two bot from the plaintext register. After that the plaintext register and the key register are shifted to the right. This process is repeated 527 times to get one block of an encrypted message. To decrypt a message a similar routine is used. <br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack a side channel is used to get the secret sender key. This side channel is the hardware. Therfore the current consumption is messured and analysed or the electromagnetic field of the semicondutor chip.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the blockcipher that it needs 528 cycles to de- or encrypt a message. With enough slide pairs (plaintext and matching encryptedt text) the steps to get the encrpted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approch the attacker tries to solve multivariate equivalations. This equivalations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://www.microchip.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2461 2020-01-12T14:55:54Z

<p>LCislo: /* Description */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic access systems, distributed by Micochip Technology Inc.. The system consists of a sender e.g. car remote key and a reciever e.g. car. In order to get access with a remote key, the reciever must learn about the remote key. For the regostration the remote key has a serial number and a secret key and the reciever has an secret manufacturer key. The registration process can be described as followed:<br /> <br /> 1) The sender send his serial number in plaintext to the reciever<br /> 2) The reciever has a secret manufacturer key. This key is used for the decryption of the serialnumber. <br /> 3) The solution to this decryption is the secret key of the sender. From this point the sender key is used to encrypt and decrypt the messages. <br /> <br /> To communicate blocks of 32bit are encrypted. One block contain a code for an action. This codes are always the same, therefore the encrypted messages would be always the same. To prevent this behavior the hopping code algorithm is used.<br /> <br /> The hopping code adds a counter to the encrypted messages. When the reciever decrypts the message the counter is read. If the recieved counter is a number within a range of 16 values difference from the last recieved counter the action is executed.<br /> <br /> To ensure that the recieved message is from the same remote key and not just a resent message from someone else the friend or foe algorithm is used. This is algorithm is an challange response algorithm. To verify the remote key the reciver sends a message in plaintext to the sender. The sender encrypts the message and send it back. If the reciever can decrypt the message correctly the remote key is verifyed. <br /> <br /> KeeloQ is an blockcipher that uses 64 bit keys on 32bit plaintext blocks. To encrypt the messages KeeloQ uses a 64bit long secret key on a 32bit long plaintext message. The encryption process takes 5bits from the plaintext register and uses them to calculate one bit with a non linear function. To get one bit from the encrypted message the solution form the non linear function is XORed with one bit from the key and two bot from the plaintext register. After that the plaintext register and the key register are shifted to the right. This process is repeated 527 times to get one block of an encrypted message. To decrypt a message a similar routine is used. <br /> <br /> === Security Threats ===<br /> <br /> ==== Side channel ==== <br /> <br /> In this attack a side channel is used to get the secret sender key. This side channel is the hardware. Therfore the current consumption is messured and analysed or the electromagnetic field of the semicondutor chip.<br /> <br /> ==== Slide attack ====<br /> <br /> This attack uses the weakness of the blockcipher that it needs 528 cycles to de- or encrypt a message. With enough slide pairs (plaintext and matching encryptedt text) the steps to get the encrpted message can be traced back to get the sender secret key.<br /> <br /> ==== Algebraic attack ====<br /> <br /> In this approch the attacker tries to solve multivariate equivalations. This equivalations must be solved for every encryption step.<br /> <br /> == References ==<br /> <br /> * https://wikipedia.org<br /> * https://google.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2460 2020-01-12T13:52:02Z

<p>LCislo: /* Summary */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and three popular attacks.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic remote keys. Every new sender e.g. remote key must be registrated on the reciever system. The new remote keys are registrated with their serial number. <br /> <br /> KeeloQ is an blockcipher that uses 64 bit keys. Every command for an action has an unique code. This code is always the same for every transmission, therefore hopping code and friend or foe algortihms are used.<br /> <br /> ==== Hopping code ====<br /> <br /> Without hopping code the transmitted code for an unique action would be every time the same. This would cause that someone who monitored the message would be able to perform the action. In hopping code a counter is used. This counter is incremented every time an action is sent. The counter value is also transmited. If the counter value if the reciever is approximately the same as the recieved the action is performed. <br /> <br /> ==== Friend or foe ====<br /> <br /> This is an challlenge response protokoll. The reciever sends an message to the sender e.g. remote key. The sender encrypts this message and sends it back to the reciever. If the messages can be decrypted successfully, further masseges from the sender will be accepted.<br /> <br /> == References ==<br /> <br /> * https://wikipedia.org<br /> * https://google.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2459 2020-01-04T00:20:23Z

<p>LCislo: /* KeeloQ */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and the hopping code and friend or foe algortihms, which are used in KeeloQ.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic remote keys. Every new sender e.g. remote key must be registrated on the reciever system. The new remote keys are registrated with their serial number. <br /> <br /> KeeloQ is an blockcipher that uses 64 bit keys. Every command for an action has an unique code. This code is always the same for every transmission, therefore hopping code and friend or foe algortihms are used.<br /> <br /> ==== Hopping code ====<br /> <br /> Without hopping code the transmitted code for an unique action would be every time the same. This would cause that someone who monitored the message would be able to perform the action. In hopping code a counter is used. This counter is incremented every time an action is sent. The counter value is also transmited. If the counter value if the reciever is approximately the same as the recieved the action is performed. <br /> <br /> ==== Friend or foe ====<br /> <br /> This is an challlenge response protokoll. The reciever sends an message to the sender e.g. remote key. The sender encrypts this message and sends it back to the reciever. If the messages can be decrypted successfully, further masseges from the sender will be accepted.<br /> <br /> == References ==<br /> <br /> * https://wikipedia.org<br /> * https://google.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2458 2020-01-04T00:20:13Z

<p>LCislo: /* KeeloQ */</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and the hopping code and friend or foe algortihms, which are used in KeeloQ.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic remote keys. Every new sender e.g. remote key must be registrated on the reciever system. The new remote keys are registrated with their serial number. <br /> <br /> <br /> KeeloQ is an blockcipher that uses 64 bit keys. Every command for an action has an unique code. This code is always the same for every transmission, therefore hopping code and friend or foe algortihms are used.<br /> <br /> ==== Hopping code ====<br /> <br /> Without hopping code the transmitted code for an unique action would be every time the same. This would cause that someone who monitored the message would be able to perform the action. In hopping code a counter is used. This counter is incremented every time an action is sent. The counter value is also transmited. If the counter value if the reciever is approximately the same as the recieved the action is performed. <br /> <br /> ==== Friend or foe ====<br /> <br /> This is an challlenge response protokoll. The reciever sends an message to the sender e.g. remote key. The sender encrypts this message and sends it back to the reciever. If the messages can be decrypted successfully, further masseges from the sender will be accepted.<br /> <br /> == References ==<br /> <br /> * https://wikipedia.org<br /> * https://google.com<br /> <br /> [[Category:Documentation]]</div>

LCislo https://elvis.hcw.ac.at/wiki/index.php?title=KeeloQ&diff=2457 2020-01-04T00:03:08Z

<p>LCislo: Created page with &quot;== Summary == This article provides an overview of KeeloQ and the hopping code and friend or foe algortihms, which are used in KeeloQ. == Requirements == * Basic knwoledge...&quot;</p> <hr /> <div>== Summary == <br /> <br /> This article provides an overview of KeeloQ and the hopping code and friend or foe algortihms, which are used in KeeloQ.<br /> <br /> == Requirements ==<br /> <br /> * Basic knwoledge of blockcipher<br /> <br /> == Description ==<br /> <br /> === KeeloQ ===<br /> <br /> KeeloQ is used for access authorization in electronic remote keys. It is an blockcipher that uses 64 bit keys.<br /> <br /> Every command for an action has an unique code. This code is always the same for every transmission, therefore hopping code and friend or foe algortihms are used.<br /> <br /> ==== Hopping code ====<br /> <br /> Without hopping code the transmitted code for an unique action would be every time the same. This would cause that someone who monitored the message would be able to perform the action. In hopping code a counter is used. This counter is incremented every time an action is sent. The counter value is also transmited. If the counter value if the reciever is approximately the same as the recieved the action is performed. <br /> <br /> ==== Friend or foe ====<br /> <br /> This is an challlenge response protokoll. The reciever sends an message to the sender e.g. remote key. The sender encrypts this message and sends it back to the reciever. If the messages can be decrypted successfully, further masseges from the sender will be accepted. <br /> <br /> == References ==<br /> <br /> * https://wikipedia.org<br /> * https://google.com<br /> <br /> [[Category:Documentation]]</div>

LCislo