The Solitaire cryptographic algorithm was designed by Bruce Schneier at the request of Neal Stephenson for use in his novel Cryptonomicon, in which field agents use it to communicate securely without having to rely on electronics or having to carry incriminating tools.[1] It was designed to be a manual cryptosystem calculated with an ordinary deck of playing cards. In Cryptonomicon, this algorithm was originally called Pontifex to hide the fact that it involved playing cards.
Pocket-RC4 22 and Solitaire 26 each use a deck of playing cards to generate a keystream, which is then added to the plaintext to get the ciphertext. Fortuitously, a standard card deck has exactly twice as many cards as there are English letters, so representing letters with cards is espe-cially easy. Would accomplish the task of implementing a method of generating encryption keys from user passwords to enhance account security. Symmetric encryption keys Would best meet the goal of a security technician that wants an application to use random salts to generate short lived encryption keys during the secure communication handshake process to. The encryption key is created and stored on the key management server. The key manager creates the encryption key through the use of a cryptographically secure random bit generator and stores the key, along with all it’s attributes, into the key storage database. Random Number Generation and Sampling Methods. In a 52-card deck of Anglo-American playing cards. Such as to generate random passwords or encryption keys, the.
One of the motivations behind Solitaire's creation is that in totalitarian environments, a deck of cards is far more affordable (and less incriminating) than a personal computer with an array of cryptological utilities. However, as Schneier warns in the appendix of Cryptonomicon, just about everyone with an interest in cryptanalysis will now know about this algorithm, so carrying a deck of cards may also be considered incriminating.
Since its creation, analysis has revealed flaws in the cipher. It is now considered insecure.
Encryption and decryption[edit]
This algorithm uses a standard deck of cards with 52 suited cards and two jokers which are distinguishable from each other, called the A joker and the B joker. For simplicity's sake, only two suits will be used in this example, clubs and diamonds. Each card is assigned a numerical value: the clubs will be numbered from 1 to 13 (Ace through King) and the diamonds will be numbered 14 through 26 in the same manner. The jokers will be assigned the values of 27 and 28. Thus, the jack of clubs would have the value 11, and the deuce of diamonds would have the value 15. (In a full deck of cards, the suits are valued in bridge order: clubs, diamonds, hearts, spades, with the suited cards numbered 1 through 52, and the jokers numbered 53 and 54.)
To begin encryption or decryption, arrange the deck of cards face-up in an order previously agreed upon. The person decrypting a message must have a deck arranged in the same order as the deck used by the person who encrypted the message. How the order is initially decided upon is up to the recipients; shuffling the deck perfectly randomly is preferable, although there are many other methods.
The algorithm generates a keystream, a sequence of values which are combined with the message to encrypt and decrypt it. Each value of the keystream is used to encrypt one character of the message, so the keystream must be at least as long as the message. If the keystream is longer than the message the message may be padded with an additional repeated character, thus denying the attacker knowledge of the exact length of the message.
To encrypt a message:
- Remove all punctuation and spaces, leaving only the 26 letters A–Z.
- Convert each letter to its natural numerical value, A = 1, B = 2, .., Z = 26.
- Generate one keystream value for each letter in the message using the keystream algorithm below.
- Add each keystream value to the corresponding plaintext number, subtracting 26 if the resulting value is greater than 26. (In mathematics this is called modular arithmetic.)
- Convert the resulting numbers back to letters. This sequence of letters is the ciphertext.
To decrypt a ciphertext:
- Convert each letter in the ciphertext to its natural numerical value.
- Generate one keystream value for each letter in the ciphertext.
- Subtract each keystream value from the corresponding ciphertext value, adding 26 if the resulting value is less than 1.
- Convert the resulting numbers back to letters.
Keystream Algorithm[edit]
This algorithm generates keystream values by moving cards within the deck. The keystream algorithm is deterministic, so the keystream values depend only on the initial order of the deck. The deck is assumed to be a circular array, meaning that should a card ever need to advance below the bottom card in the deck, it will simply rotate back to the top (in other words, the first card follows the last card).We will take for example this starting deck:
- 1 4 7 10 13 16 19 22 25 28 3 6 9 12 15 18 21 24 27 2 5 8 11 14 17 20 23 26
Perform these steps to generate one character of the keystream.
- Locate the A joker (value 27) and move it down the deck by one place. If it is the last card, it becomes the second card. There is no way for it to become the first card. The deck now looks like this:
- 1 4 7 10 13 16 19 22 25 28 3 6 9 12 15 18 21 24 2 27 5 8 11 14 17 20 23 26
- Locate the B joker (value 28) and move it down the deck by two places. Notice that if it is the second to last card, it becomes the second card by wrapping around. If it is the last card, it becomes the third card. There is no way for it to become the first card.
- 1 4 7 10 13 16 19 22 25 3 6 28 9 12 15 18 21 24 2 27 5 8 11 14 17 20 23 26
- Perform a 'triple cut': split the deck into three sections. Everything above the top joker (which, after several repetitions, may not necessarily be the A joker) and everything below the bottom joker will be exchanged. The jokers themselves, and the cards between them, are left untouched.
- 5 8 11 14 17 20 23 26 28 9 12 15 18 21 24 2 27 1 4 7 10 13 16 19 22 25 3 6
- Perform a 'count cut': observe the value of the card at the bottom of the deck. If the card is either joker take its value to be 27. Remove that number of cards from the top of the deck and insert them just above the last card in the deck.
- 23 26 28 9 12 15 18 21 24 2 27 1 4 7 10 13 16 19 22 25 3 5 8 11 14 17 20 6
- Now, look at the value of the top card. Again, either joker counts as 27. Count this many places below that card and take the value of that card as the next value in the keystream. If the card counted to is either joker, ignore it and repeat the keystream algorithm. In this example the top card is 23, so we count to the 24th card, which is 11; thus the keystream value is 11. (Note that no cards change places in this step, this step simply determines the keystream value).
Cryptanalysis[edit]
In 1999 Paul Crowley discovered that there is a bias towards repeating characters in the keystream, which occur about every 1/22.5 characters rather than the expected 1/26.[2] As a result, Solitaire leaks information at a rate of about 0.0005 bits per character.[3] While its security may perhaps be adequate for very short messages, in general Solitaire is considered insecure.
Crowley also noticed that in some cases, there are two different deck configurations which result in the same configuration after executing the keystream algorithm. For instance, when the A joker is either on the bottom of the deck or on the top of the deck it will become the second card after step 1. This means the algorithm is not always reversible as Schneier had originally claimed.[2] Cod4 mw key code generator.
In 2019 Daniel Shiu proposed modifications to the algorithm which would increase its security, at the cost of making it more difficult for the user to implement manually.[3]
References[edit]
- ^Schneier, Bruce (May 1999). 'Solitaire'. Retrieved 2 July 2006.
- ^ abCrowley, Paul. 'Problems with Bruce Schneier's 'Solitaire''. Retrieved 26 March 2018.
- ^ abShiu, Daniel (13 Sep 2019). 'Analysis of Solitaire'(PDF). Retrieved 18 Oct 2019.
External links[edit]
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Solitaire_(cipher)&oldid=947837039'
What is Credit Card Encryption?
Credit card encryption is a security measure used to reduce the likelihood of a credit or debit card information being stolen. Credit card encryption involves both the security of the card, the security of the terminal where a card is scanned, and the security of the transmission of the card’s information between the terminal and a back-end computer system. Windows xp home edition cd key generator download.
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Credit cards are an integral part of the payment process. Consumers expect that most businesses will accept cards as a method of payment, rather than relying on cash to conduct transactions. Businesses provide electronic terminals that a consumer can scan his or her credit card through, with the terminals sending the card’s identifying information to computer servers in order to verify that the consumer has sufficient funds.
How Credit Card Encryption Works
When a credit account holder makes a purchase with their card, the information such as the account number is scrambled by an algorithm. The intent is to make it impossible to access that information without the corresponding encryption key that lets the merchant and financial institution conduct their transactions. Until the information is decrypted by the key, the information is not usable, making it safe so long as it remains unlocked.
Because credit cards require the use of an electronic transfer of information, they can be exposed to third parties who can steal the card’s information. Types of fraud include skimming, carding, and RAM scraping.
Card issuers use a variety of methods to encrypt credit cards. The magnetic strip on the back of a card is typically encrypted and can only be read by a card scanner. Relying solely on the magnetic strip is a less secure method than requiring the use of a PIN-and-chip, because a PIN makes it more difficult for stolen credit cards to be authorized and used. A smart card with an electronic chip adds can be harder for thieves and hackers to steal information from, compared with other forms of encryption and security put in place to protect cred account information.
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For transactions that do not require a card to be scanned, such as an online transaction or in-app purchase, websites require both the credit card number on the front of the card and a CVV number located on the back of the card to be used. Using a CVV prevents an individual from being able to use only a stolen credit card number to conduct a transaction. https://poweruptd.weebly.com/random-key-generator-php-code.html.
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- Credit card encryption is a security measure used to reduce the likelihood of a credit or debit card information being stolen
- It makes it impossible to access the credit card information without the corresponding encryption key that lets the merchant and financial institution conduct their transactions.
- Card issuers use many methods to encrypt credit cards including magnetic strips, PIN numbers, electronic chips and a CVV in case of online transactions.