Artwork

المحتوى المقدم من Mohamed Elsherif. يتم تحميل جميع محتويات البودكاست بما في ذلك الحلقات والرسومات وأوصاف البودكاست وتقديمها مباشرةً بواسطة Mohamed Elsherif أو شريك منصة البودكاست الخاص بهم. إذا كنت تعتقد أن شخصًا ما يستخدم عملك المحمي بحقوق الطبع والنشر دون إذنك، فيمكنك اتباع العملية الموضحة هنا https://ar.player.fm/legal.
Player FM - تطبيق بودكاست
انتقل إلى وضع عدم الاتصال باستخدام تطبيق Player FM !

EP47 - AskDeveloper Podcast - Cryptography - Part 2 - Encryption

1:09:10
 
مشاركة
 

Manage episode 163272688 series 26781
المحتوى المقدم من Mohamed Elsherif. يتم تحميل جميع محتويات البودكاست بما في ذلك الحلقات والرسومات وأوصاف البودكاست وتقديمها مباشرةً بواسطة Mohamed Elsherif أو شريك منصة البودكاست الخاص بهم. إذا كنت تعتقد أن شخصًا ما يستخدم عملك المحمي بحقوق الطبع والنشر دون إذنك، فيمكنك اتباع العملية الموضحة هنا https://ar.player.fm/legal.
?????? ??????? https://soundcloud.com/askdeveloper/ep46-askdeveloper-podcast-cryptography-part-1-introduction-and-hashing ? Encryption (Two Ways) § Symmetric Encryption ? Same key both encrypts and decrypts the data. ? Very fast, yet exchanging key is tricky ? Very Algorithmic ? Examples ® DES Data Encryption Standard (BROKEN) ? Uses key of 56 bit length ® Triple DES (3DES) ? Uses three keys (or two unique keys) of 56 bit each ® AES Advanced Encryption Standard ? Uses keys of 128, 192 or 256 bits long ? Attacks ® Brute force ? Usually mitigated via increasing key length, as difficulty increases exponentially as key size increases, for example time to crack given a modern super computer. Key Size Time To Crack 56 bits 399 seconds 128 bits 1.02 * 1018 years 192 bits 1.87 * 1037 years 256 bits 3.31 * 1056 years ? Side-Channel Attacks § Asymmetric Encryption ? Key pairs have mathematical relationship ? Each one can decrypt messages encrypted by the other. ? Slow, but exchanging key is trivial ? Very Mathematical ? Anyone can know the Public Key ® The Public key can only be used to encrypt data ? The Private key is kept secret, and never leaves the recipient's side. ® The Private key can only be used to decrypt data ? Examples ® RSA (Rivest, Shamir and Adelman) ® The de-facto standard in the industry ® Public and Private keys are based on large Prime Numbers § Hybrid Encryption ? Uses both Symmetric and Asymmetric encryption at the same time. ? Goals: ® Use the performance of Symmetric Crypto ® Convenience of sharing keys using Asymmetric Crypto ® HMAC for authentication. ? Steps: (Order is very important) ® Party 1 (Alice) 1. Generates a random AES Session Key (32 bytes / 256 bits) 2. Generates a random Initialization Vector (IV) (16 bytes / 128 bits) 3. Encrypt the message to be sent using the AES Session Key & IV 4. Calculate an HMAC of the encrypted message using the AES Session key 5. Encrypt the AES Session Key using the Public Key of Party 2 (Bob) The recipient. 6. Sends a packet of (Encrypted Message, Encrypted Session Key, Initialization Vector, and HMAC) to Bob ® Party 2 (Bob) 1. Decrypts Session key using his Private Key 2. Recalculates the HMAC of the encrypted message (Validates message integrity) } If HMAC check pass – Decrypts the message using the decrypted AES Session Key and Initialization Vector } Otherwise, rejects the message because of integrity check failure. Our facebook Page http://facebook.com/askdeveloper On Sound Cloud http://soundcloud.com/askdeveloper Please Like & Subscribe
  continue reading

83 حلقات

Artwork
iconمشاركة
 
Manage episode 163272688 series 26781
المحتوى المقدم من Mohamed Elsherif. يتم تحميل جميع محتويات البودكاست بما في ذلك الحلقات والرسومات وأوصاف البودكاست وتقديمها مباشرةً بواسطة Mohamed Elsherif أو شريك منصة البودكاست الخاص بهم. إذا كنت تعتقد أن شخصًا ما يستخدم عملك المحمي بحقوق الطبع والنشر دون إذنك، فيمكنك اتباع العملية الموضحة هنا https://ar.player.fm/legal.
?????? ??????? https://soundcloud.com/askdeveloper/ep46-askdeveloper-podcast-cryptography-part-1-introduction-and-hashing ? Encryption (Two Ways) § Symmetric Encryption ? Same key both encrypts and decrypts the data. ? Very fast, yet exchanging key is tricky ? Very Algorithmic ? Examples ® DES Data Encryption Standard (BROKEN) ? Uses key of 56 bit length ® Triple DES (3DES) ? Uses three keys (or two unique keys) of 56 bit each ® AES Advanced Encryption Standard ? Uses keys of 128, 192 or 256 bits long ? Attacks ® Brute force ? Usually mitigated via increasing key length, as difficulty increases exponentially as key size increases, for example time to crack given a modern super computer. Key Size Time To Crack 56 bits 399 seconds 128 bits 1.02 * 1018 years 192 bits 1.87 * 1037 years 256 bits 3.31 * 1056 years ? Side-Channel Attacks § Asymmetric Encryption ? Key pairs have mathematical relationship ? Each one can decrypt messages encrypted by the other. ? Slow, but exchanging key is trivial ? Very Mathematical ? Anyone can know the Public Key ® The Public key can only be used to encrypt data ? The Private key is kept secret, and never leaves the recipient's side. ® The Private key can only be used to decrypt data ? Examples ® RSA (Rivest, Shamir and Adelman) ® The de-facto standard in the industry ® Public and Private keys are based on large Prime Numbers § Hybrid Encryption ? Uses both Symmetric and Asymmetric encryption at the same time. ? Goals: ® Use the performance of Symmetric Crypto ® Convenience of sharing keys using Asymmetric Crypto ® HMAC for authentication. ? Steps: (Order is very important) ® Party 1 (Alice) 1. Generates a random AES Session Key (32 bytes / 256 bits) 2. Generates a random Initialization Vector (IV) (16 bytes / 128 bits) 3. Encrypt the message to be sent using the AES Session Key & IV 4. Calculate an HMAC of the encrypted message using the AES Session key 5. Encrypt the AES Session Key using the Public Key of Party 2 (Bob) The recipient. 6. Sends a packet of (Encrypted Message, Encrypted Session Key, Initialization Vector, and HMAC) to Bob ® Party 2 (Bob) 1. Decrypts Session key using his Private Key 2. Recalculates the HMAC of the encrypted message (Validates message integrity) } If HMAC check pass – Decrypts the message using the decrypted AES Session Key and Initialization Vector } Otherwise, rejects the message because of integrity check failure. Our facebook Page http://facebook.com/askdeveloper On Sound Cloud http://soundcloud.com/askdeveloper Please Like & Subscribe
  continue reading

83 حلقات

Todos los episodios

×
 
Loading …

مرحبًا بك في مشغل أف ام!

يقوم برنامج مشغل أف أم بمسح الويب للحصول على بودكاست عالية الجودة لتستمتع بها الآن. إنه أفضل تطبيق بودكاست ويعمل على أجهزة اندرويد والأيفون والويب. قم بالتسجيل لمزامنة الاشتراكات عبر الأجهزة.

 

دليل مرجعي سريع