Luu Pham GMU - Dec. 03Cryptography Software ToolsGMU GMU ––December 2001December 2001Luu PhamLuu PhamLuu Pham GMU - Dec. 03Cryptography Software ToolsAGENDAAGENDA Project Overview Highlight of RSA Algorithm Main features of the software• Calculation tools• RSA encryption - decryption• RSA signature• Setup – Admin mini database Demo Problems & Lessons learned Conclusions & SuggestionsLuu Pham GMU - Dec. 03Cryptography Software ToolsPROJECT OVERVIEWPROJECT OVERVIEWPROJECT OVERVIEWPROJECT OVERVIEWEncryptionEncryptionDecryptionDecryptionBOBBOBALICEALICELuu Pham GMU - Dec. 03Cryptography Software ToolsPROJECT OVERVIEWPROJECT OVERVIEWPROJECT OVERVIEWPROJECT OVERVIEW Cryptographic products: •Tightly integrated with applications• End to end embedded Users unable to: •See main processes of crypto-algorithm• Manipulate inputs/Outputs• Observe intermediate values Difficult for cryptographic learners•An Attempt to fill the gap!FACTS FACTSLuu Pham GMU - Dec. 03Cryptography Software ToolsPROJECT OVERVIEWPROJECT OVERVIEWPROJECT OVERVIEWPROJECT OVERVIEW User friendly interface Extended Visualizations Users able to:• See main processes of crypto-algorithm• Manipulate Inputs/Outputs• Observe intermediate values Have fun to consolidate course materialLuu Pham GMU - Dec. 03Cryptography Software ToolsPUBLIC KEY Vs. SECRET KEY PUBLIC KEY Vs. SECRET KEY Secret Key:BOBBOBALICEALICE• Has been used for thousands of years• Uses same key to encrypt – decrypt• Need a secure channel to exchange/agree keyLuu Pham GMU - Dec. 03Cryptography Software ToolsPUBLIC KEY Vs. SECRET KEY PUBLIC KEY Vs. SECRET KEY Public Key:BOBBOBALICEALICE• 1976: Concepts of public key (Diffie and Hellman)• 1977: RSA public key published, then widely used • Encrypt: using public key pair• Decrypt: using secret key pair• There is no need the secure channelLuu Pham GMU - Dec. 03Cryptography Software ToolsRSA ALGORITHMRSA ALGORITHM RSA: Rivest-Shamir-Adleman (Aug, 1977) Security:• Relies on difficulty of factoring large prime numbers Most commonly used in industry Used for:•Privacy (Encryption / Decryption)• Authentication (Digital Signature / DS Verification)Luu Pham GMU - Dec. 03Cryptography Software ToolsRSA KEY GENERATIONRSA KEY GENERATIONGenerate large primes: p, qqp≠Compute N=p*q; Phi=(p-1)(q-1)Select e: 1<e<Phi GCD(e,Phi)=1Compute d: 1<d<Phi ed=1 mod PhiPublic Keys[e,N]Private Keys[d,N]Luu Pham GMU - Dec. 03Cryptography Software ToolsRSA ENCRYPTION / DECRYPTIONRSA ENCRYPTION / DECRYPTIONPLAIN TEXTPLAIN TEXTCIPHER TEXTCIPHER TEXTC=MC=MEEmod Nmod NM=CM=CDDmod Nmod NBOBBOBPublic Keys[E, N]ALICEALICEAliceAlice’’s public keyss public keysPrivate Keys[D, N]AliceAlice’’s private keyss private keysLuu Pham GMU - Dec. 03Cryptography Software ToolsRSA SIGNATURERSA SIGNATUREBOBBOBALICEALICESignatureSignatureMessage MRSA AlgorithmS=h^d mod NHash function h=h(M)Bob’s private keysBobBob’’s Signatures SignatureLuu Pham GMU - Dec. 03Cryptography Software ToolsRSA SIGNATURE VERIFICATIONRSA SIGNATURE VERIFICATIONHash function h2=h(M)Message MRSA Algorithmh1=S^e mod NBob’s public keys[e, N]BOBBOBALICEALICEBobBob’’s Signatures Signatureh1=h2?h1=h2?YYACCEPTACCEPTNNREJECTREJECTh1h1h2h2Luu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES OF THE APPLICATIONMAIN FEATURES OF THE APPLICATIONRSA privacy (32RSA privacy (32--bit key lengths)bit key lengths)RSA Signature (MD5 hash function)RSA Signature (MD5 hash function)Certification Authority (planned)Certification Authority (planned)Calculation UtilityCalculation UtilityDatabase UtilityDatabase UtilityUseful linksUseful linksLuu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES OF SOFTWARE TOOLSMAIN FEATURES OF SOFTWARE TOOLS RSA Privacy (32-bit key lengths): •Encryption - Decryption RSA Authentication (MD5 hash):• Signature / Signature verification Calculation utilities• GCD, Linear congruence• Multiplicative inverse• Binary Exponentiation• Calculations needed for RSA algorithm Database utilityLuu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES MAIN FEATURES --RSA EncryptionRSA EncryptionSearch public keys for the receiverSearch public keys for the receiver--By IDBy ID--By Last nameBy Last name--By First name By First name Load message want to sendLoad message want to send--By typing in message boxBy typing in message box--By load from text fileBy load from text fileEncrypt messageEncrypt message--Intermediate values show in iterative boxIntermediate values show in iterative boxOption to save all calculation to text fileOption to save all calculation to text fileLuu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES MAIN FEATURES --RSA DecryptionRSA DecryptionAll calculations are shown hereAll calculations are shown hereLuu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES MAIN FEATURES --RSA SignatureRSA SignatureSender info and private keysSender info and private keysReceiver info and public keysReceiver info and public keysDigital signature and its calculations are shownDigital signature and its calculations are shownLuu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES MAIN FEATURES --RSA Signature VerificationRSA Signature VerificationDecrypt Signature using Decrypt Signature using sendersender’’s public keys.s public keys.Get hash value #2Get hash value #2Decrypt Cipher text to get Decrypt Cipher text to get the original messagethe original messageGet hash value by running Get hash value by running h1=h(message)h1=h(message)Verify Digital Signature by Verify Digital Signature by comparing h1 and h2comparing h1 and h2Luu Pham GMU - Dec. 03Cryptography Software ToolsMAIN FEATURES MAIN FEATURES --Calculation ToolsCalculation ToolsCalculation MenuCalculation MenuLuu Pham GMU - Dec. 03Cryptography Software ToolsCalculation Tools Calculation Tools ––Binary ExponentialBinary ExponentialLeft To Right Left To Right AlgorithmAlgorithmRight To Left Right To Left AlgorithmAlgorithmLuu Pham GMU - Dec. 03Cryptography Software ToolsCalculation Tools Calculation Tools --RSA Key CalculationsRSA Key CalculationsLuu Pham GMU - Dec. 03Cryptography Software ToolsCalculation Tools Calculation Tools ––Linear CongruenceLinear CongruenceLuu Pham GMU - Dec. 03Cryptography Software ToolsCalculation Tools Calculation Tools ––MD5 hash functionMD5 hash
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