Microsoft Technology Licensing, LLC

Yu Lin Sie

Kedarnath Atmaram Dubhashi

Anand Paka

Jorge Pereira

Roy Williams

Jonathan D Schwartz

Philip Joseph Hallin

Karim Batthish

Phillip J Hallin

Various embodiments enable so-called extended data to be added to a signed digital certificate without having a private key of a Certification Authority available. In at least some embodiments, a request to add extended data to a digital certificate generated by a certificate authority is received from a client device. The digital certificate includes a signed first portion, and an unsigned second portion that includes reserved empty spaces that are reserved for the extended data. The extended data is added to the unsigned second portion. the extended data includes a client ID associated with the client device. The unsigned portion of the digital certificate is signed after the extended data is added.

Extended data signing

Various embodiments enable so-called extended data to be added to a signed digital certificate without having a private key of a Certification Authority available. In at least some embodiments, a digital certificate can be issued and signed off line by the Certification Authority, and then later extended data can be added and signed using another key, whose public key was earlier embedded and signed in the certificate.

Systems and methods for validating integrity of an executable file are described. In one aspect, multiple partial image hashes are generated, the combination of which represent a digest of an entire executable file. Subsequent to loading the executable file on a computing device, a request to page a portion of the executable file into memory for execution is intercepted. Responsive to intercepting the request, and prior to paging the portion into memory for execution, a validation hash of the portion is computed. The validation hash is compared to a partial hash of the multiple partial image hashes to determine code integrity of the portion. The partial hash represents a same code segment as the portion.

Systems and methods for validating executable file integrity using partial image hashes

A certificate-based encryption mechanism in which a source client does not access the entire certificate corresponding to a destination client when encrypting an electronic message to be sent to the destination client. Instead, the source client only requests a portion of the certificate from a certificate server. That portion includes encryption information, but may lack some or even all of the self-verification information in the certificate. The certificate server preferably performs any validation of the certificate prior to sending the encryption information to the source client. The certificate need not be separately validated by the source client, especially if the certificate server is trusted by the source client.

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Bellevue, WA, United States of America

Yu Lin Sie