Granted Patent B2

US 12,554,475 · App. 18/084,683 · Granted Feb 17, 2026

Inventors: Kai-Min Sung (Foster City, CA); Nir Peer (Ramat Gan, IL)

Assignee: Digital Turbine, Inc.

G06F8/61H04L9/30H04L9/3247

Abstract

Claims (66)

1 . A verification server for securing application installation on a user device, comprising processing circuitry configured to:

input, from a user device, a request for automatic installation of said application onto said user device, said request comprising a request signature included in a link selected by a user of said user device;

verify a validity of said request signature using a first key associated with a second key used to generate valid signatures in response to received requests for secured links each comprising respective values of at least one parameter used to create a valid signature, said at least one parameter comprises a device identifier;

when said request signature is valid, respond to said user device that said automatic installation is authorized; and

when said request signature is invalid, respond to said user device that said automatic installation is prohibited.

2 . The verification server of claim 1 , wherein said first key and said second key are identical.

3 . The verification server of claim 1 , wherein said first key comprises a public key and said second key comprises a private key corresponding to said public key.

4 . The verification server of claim 1 , wherein said request for automatic installation comprises respective values of said at least one parameter.

5 . The verification server of claim 4 , wherein said verification server being configured to verify said validity of said request signature by:

forming a first string from said at least one parameter values according to rules used to generate a signature string for a valid secured link;

decrypting said request signature using said first key; and

comparing said first string to said decrypted request signature, said request signature being

valid when said first string and said decrypted request signature are the same and invalid when said first string and said decrypted request signature are different.

6 . The verification server of claim 5 , wherein said forming said first string comprises performing a hashing operation on a preliminary string formed from said at least one parameter values, using a same hashing algorithm used to generate valid signatures.

7 . The verification server of claim 1 , wherein said at least one parameter used to create a valid signature further comprises at least one of:

a signature version identifier;

an application identifier;

a cryptographic nonce; and

an expiration timestamp.

8 . The verification server of claim 1 , further configured to prohibit said automatic installation when an expiration timestamp for said request has expired.

9 . The verification server of claim 1 , further configured to prohibit said automatic installation when a request for automatic installation received from said user device is missing a request signature.

10 . A method for securing application installation on a user device, comprising: inputting, from said user device, a request for automatic installation of said application onto said user device, said request comprising a request signature included in a link selected by a user of said user device;

verifying a validity of said request signature using a first key associated with a second key used to generate valid signatures in response to received requests for secured links each comprising respective values of at least one parameter used to create a valid signature, said at least one parameter comprises a device identifier;

when said request signature is valid, responding to said user device that said automatic installation is authorized; and

when said request signature is invalid, responding to said user device that said automatic installation is prohibited.

11 . The method of claim 10 , wherein said first key and said second key are identical.

12 . The method of claim 10 , wherein said first key comprises a public key and said second key comprises a private key corresponding to said public key.

13 . The method of claim 10 , wherein said request for automatic installation comprises respective values of said at least one parameter.

14 . The method of claim 10 , wherein said at least one parameter used to create a valid signature further comprises at least one of:

a signature version identifier;

an application identifier;

a cryptographic nonce; and

an expiration timestamp.

15 . The method of claim 10 , wherein verifying said validity of said request signature comprises:

forming a first string from said at least one parameter values in accordance with rules used to generate a signature string for encryption into a valid signature;

decrypting said request signature using said first key; and

comparing said first string to said decrypted request signature, said request signature being valid when said first string and said decrypted request signature are the same and invalid when said first string and said decrypted request signature are different.

16 . The method of claim 15 , wherein said forming a first string comprises hashing a preliminary string formed from said at least one parameter value, using a same hashing algorithm used to generate valid signatures.

17 . The method of claim 10 , further comprising prohibiting said automatic installation when an expiration timestamp for said request has expired.

18 . The method of claim 10 , further comprising prohibiting said automatic installation when a request for automatic installation received from said user device is missing a request signature.

19 . A system for securing application installation on a user device, comprising:

a secure link server comprising processing circuitry configured to:

output a secured link for automatically downloading and installing an application onto a user device in response to a received request for said secured link comprising respective values of at least one parameter used to create a valid signature, said at least one parameter comprises a device identifier, said secured link comprising a signature string encrypted with a first key; and

a verification server comprising processing circuitry configured to:

input, from said user device, a request for automatic installation of said application onto said user device, said request for automatic installation comprising a request signature included in a link selected by a user of said user device;

verify a validity of said request signature using a second key associated with said first key;

when said request signature is valid, respond to said user device that said automatic installation is authorized; and

when said request signature is invalid, respond to said user device that said automatic installation is prohibited.

20 . The system of claim 19 , further comprising a first secure vault for providing said first key to said secure link server and a second secure vault for providing said second key to said verification server.

21 . The system of claim 19 , wherein said first key and said second key are identical.

22 . The system of claim 19 , wherein said first key comprises a private key and said second key comprises a public key corresponding to said private key.

23 . The system of claim 19 , wherein said secure link server is configured to generate said secured link by:

forming a first string from said at least one parameter value in accordance with specified rules;

encrypting said first string with said first key; and

creating a secured link comprising said encrypted first string and said at least one parameter value.

24 . The system of claim 19 , wherein said secure link server is configured to generate said secured link by:

forming a first string from said at least one parameter value in accordance with specified rules;

signing said first string with said first key; and

creating a secured link comprising said encrypted first string and said at least one parameter value.

25 . The system of claim 19 , wherein said secure link server outputs said secured link to one of:

a content server for forwarding said secured link to be rendered in content displayed on said user device; and

said user device.

26 . The system of claim 19 , wherein said request for automatic installation further comprises respective values of said at least one parameter, and wherein said verification server is configured to verify said validity of said request signature by:

forming, in accordance with rules used by said secure link server to create a valid signature string, a second string from respective values of said at least one parameter extracted from said request for automatic installation;

decrypting said request signature using said second key; and

comparing said second string to said decrypted request signature, said request signature being valid when said second string and said decrypted request signature are the same and invalid when said second string and said decrypted request signature are different.

Assignments (4)

Continuity (1)

References Cited (9)