Forward Security Adaptive Cryptography: Time Evolution

Gene Itkis, Boston University

Security and Secret Keys

Introduction by Example: Forward Secure Signatures

Digital Signatures

Limitations of Signatures

Key Security

Threshold Crypto: Space Dimension

Proactive Crypto: Time Evolution of Sharing

Limits of Proactive Security

Price of Proactive/Threshold Security

Key Evolution

Threshold and Forward Security: Overview

Threshold and Proactive Cryptography

Forward Secure Cryptography

Key Evolution: Functional Definitions for Forward Security

Common Procedures

Specific Example: Forward Secure Signatures

Security Definitions

Forward Secure Pseudorandom Generators



Symmetric Cryptography: From fsPRG to fsMAC, Audit Logs, and Encryption

Forward Secure Public Key Crypto: Naive Generic Construction

Forward Secure Signatures

Generic Constructions

Concrete Constructions

Time Period Bound

Time–Space Trade-off: Pebbling

Forward-Secure Public Key Encryption


Forward Security: Open Problems

Evolving Cryptography: Beyond Forward Security

From Theory to Practice


Cross References




As our world is growing increasingly dependent on digital systems, security of these systems is becoming increasingly critical. In addition to accidental failures, threats of malicious attacks must be addressed by the security systems of today and tomorrow.

Connectivity of the digital systems has become an integral part of their functionality. ...

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