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Information Security & Cryptographic Principles. Infosec and Cryptography Subjects / Topics : 1. Introduction to computer cryptography 2. Single key cryptographic algorithms 3. Public key cryptographic algorithms 4. Crypto Applications 5. Business Continuity.
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Information Security & Cryptographic Principles
Infosec and Cryptography Subjects / Topics : 1. Introduction to computer cryptography 2. Single key cryptographic algorithms 3. Public key cryptographic algorithms 4. Crypto Applications 5. Business Continuity
IntranetExtranet Internet Bob Alice Basic Problem There are Confidence and Trust Issues …
Multiple Security Issues Privacy Authentication Interception Spoofing Integrity Non-repudiation Not sent not received Claims Proof of parties involved Modification
Information Security Confidentiality Integrity Availability
Security Services Integrity Information has not been altered Confidentiality Content hidden during transport Authentication Identity of originator confirmed Non-Repudiation Originator cannot repudiate transaction
Some confidential text (message) in clear (readable) form Data Confidentiality
Cryptography Someconfid entialtext essage) in clear Some confidential text (message) in clear (readable) form E n c r y p t i o n
Cryptography Someconfid entialtext essage) in clear Some confidential text (message) in clear (readable) form D e c r y p t i o n
Some confidential text (message) in clear (readable) form Crypto Transformations • Someconfi • Entialte • essage) • in clear
Some confidential text (message) in clear (readable) form Crypto Transformations • Someconfi • Entialte • essage) • in clear
Someconfid entialtext essage) in clear Someconfid entialtext essage) in clear Someconfid entialtext essage) in clear Someconfid entialtext essage) in clear Someconfid entialtext essage) in clear Someconfid entialtext essage) in clear Someconfid entialtext essage) in clear Parameterization Some confidential text (message) in clear (readable) form • Someconfi • Entialte • essage) • in clear Crypto key
Infosec and Cryptography Subjects / Topics : 1. Introduction to computer cryptography 2. Single key cryptographic algorithms 3. Public key cryptographic algorithms 4. Crypto Applications 5. Business Continuity
E n c r y p t i o n Someconfid Entialtext essage) in clear Some confidential text (message) in clear (readable) form D e c r y p t i o n Single Key Crypto Crypto key
How to design good cryptographic systems ?What does it mean good crypto system ? Design . . . ?
Principles 1. Simple for users 2. Complicated for intruders 3. Public algorithm 4. Secret key 5. Large number of combinations 6. Special properties
Other Symmetric Algorithms 1. AES 2. IDEA 3. Triple - DES 4. RC-2 5. RC-4 6. Blowfish
Infosec and Cryptography Subjects / Topics : 1. Introduction to computer cryptography 2. Single key cryptographic algorithms 3. Public key cryptographic algorithms 4. Crypto Applications 5. Business Continuity
E n c r y p t i o n D e c r y p t i o n Secret Key Systems Someconfi entialtext essage) in clear Some confidential text (message) in clear (readable) form Crypto key
? Key Exchange
Public Key Cryptography Encryption Key 2 Some confidential text (message) in clear (readable) form Someconfi entialtext essage) in clear Key 1 Decryption
Public Key Cryptography Bob Alice MSG tia Encryption Decryption MSG Bob Private Alice Private Bob Public Alice Public Digital Signature … Authentication … Non-Repudiation
Public Key Cryptography Bob Alice MSG tia Encryption Decryption MSG Bob Private Alice Private Bob Public Alice Public Confidentiality
Symmetric and Asymmetric Encryption • Symmetric: Faster than asymmetric, hard to break with large key, hard to distribute keys, too many keys required, cannot authenticate or provide non-repudiation. • Includes: DES, Triple DES, Blowfish, IDEA, RC4, RC5, RC6, AES
Asymmetric cryptography: Better at key distribution, better scalability for large systems, can provide authentication and non-repudiation, slow, math intensive Includes: RSA, ECC, Diffie Hellman, El Gamal, DSA, Knapsack, PGP Symmetric and Asymmetric Encryption
Infosec and Cryptography Subjects / Topics : 1. Introduction to computer cryptography 2. Single key cryptographic algorithms 3. Public key cryptographic algorithms 4. Crypto Applications 5. Business Continuity
Crypto Applications 1. Digital signature 2. Digital enveloping 3. Digital certificates 4. Secret key exchange
Digital Signature A Digital Signature is a data item that vouches for the origin and the integrity of a Message Intranet Extranet Internet Alice Bob
Digital Signature Message Message Digest Algorithm Digest Algorithm Hash Function Hash Function Digest Public Key Encryption Decryption Private Key Expected Digest Actual Digest Signature Signer Receiver Channel
Digital Signature “Real Identity” of the Signer. Why should I trust what the Sender claims to be ? Moving towards PKI …
Digital Certificate A Digital Certificate is a binding between an entity’s Public Key and one or more Attributes related to its Identity. The entity can be a Person, an Hardware Component, a Service, etc. • A Digital Certificate is issued (and signed) by someone : • Usually the issuer is a Trusted Third Party
CERTIFICATE Digital Certificate Subject Issuer Subject Public Key Issuer Digital Signature
Digital Certificate • How are Digital Certificates Issued? • Who is issuing them? • Why should I Trust the Certificate Issuer? • How can I check if a Certificate is valid? • How can I revoke a Certificate? • Who is revoking Certificates? Moving towards PKI …
Infosec and Cryptography Subjects / Topics : 1. Introduction to computer cryptography 2. Single key cryptographic algorithms 3. Public key cryptographic algorithms 4. Crypto Applications 5. Business Continuity
Business Continuity and Disaster Recovery • Businesses are more susceptible to failure after a disaster • Goal • To minimize disaster aftermath and ensure resources, personnel, and business processes resume • By • Planning measures • Backing up data and hardware • Getting the right people in place • Requirements • Management support • Driving the project, top-down approach • Must understand value of investing in BCP • Returns can be priceless
Business Continuity Steps • Steps • Develop the continuity planning policy statement • Conduct the business impact analysis (BIA) • Identify preventive controls • Develop recovery strategies • Develop the contingency plan • Test the plan and conduct training and exercises • Maintain the plan • Understanding the Organization
Business Impact AnalysisBIA • Considered a functional analysis • Team collects data in variety of ways • Maps out following characteristics: • Maximum tolerable downtime • Operational disruption and productivity • Financial considerations • Regulatory responsibilities • Reputation • Understand the variety of possible threats • Must go through all possible scenarios