Emc Corporation

Emc IP Holding Company LLC

Other

Marten Van Dijk

Ari Juels

Nikolaos Triandopoulos

Kevin Bowers

Ronald L Rivest

Samuel Curry

John Gordon Brainard

Alina Oprea

Sean Patrick Doyle

Riaz Zolfonoon

Eyal Kolman

Emil P Stefanov

William Duane

Roy Hodgman

Michael J O'Malley

Robert Damon Hopley

Rachael Stockton

Kenneth D Ray

Karl Ackerman

John G Linn

Brian William Fitzgerald

George Matthews

Emily Shen

Methods and apparatus are provided for randomizing state transitions for one-time authentication tokens. A user authentication passcode is generated by determining a generation time within an epoch for initiating computation of the user authentication passcode; initiating computation of the user authentication passcode at the determined generation time; and presenting the user authentication passcode at a presentation time that is de-coupled from the generation time. The generation time occurs, for example, at a random offset from a start of the epoch. A time difference between the presentation time and a completion of the computation of the user authentication passcode comprises, e.g., a uniformly distributed random variable over a range of values having a finite mean value. The epoch optionally comprises pre-computation epochs and a variable number of user authentication passcodes are optionally computed during a given pre-computation epoch. The number of passcodes generated per epoch can be varied in a random manner.

Randomizing state transitions for one-time authentication tokens

A server is configured to communicate with a group of clients over a network in one embodiment. The server maps the group of clients into a plurality of subgroups of bounded size, communicates to a given one of the clients information identifying the particular subgroup to which that client belongs as well as the other clients in that subgroup. The given client utilizes the communicated information to generate a ring signature over the corresponding subgroup of clients based on the communicated information. The subgroup size may be bounded to a minimum size and a maximum size in accordance with a variable privacy parameter. The server can increase or decrease the value of the parameter in order to provide respective increased or decreased privacy to the clients, by making it respectively more or less difficult to determine which client in a corresponding one of the subgroups produced the received ring signature.

Dynamic privacy management for communications of clients in privacy-preserving groups

Methods and apparatus are provided for improving resilience to forward clock attacks. A token generates a passcode from a user authentication token for presentation to an authentication server by detecting a forward clock attack; and communicating an indication of the forward clock attack to the authentication server. The generation of the user authentication passcodes is optionally suspended upon detecting the forward clock attack. The detection may be based on a comparison of a current device time of the token and a last used device time during a generation of a user authentication passcode.

Time synchronization solutions for forward-secure one-time authentication tokens

A first cryptographic device is authenticated by a second cryptographic device. The second cryptographic device stores an alternative version of a secret value associated with the first cryptographic device as a countermeasure to compromise of the secret value. In conjunction with a protocol carried out between the first cryptographic device and the second cryptographic device, the second cryptographic device determines the secret value based at least in part on the alternative version of the secret value, and utilizes the determined secret value to authenticate the first cryptographic device. The alternative version of the secret value may comprise a randomly-skewed version of the secret value. For example, the secret value may comprise a key or other parameter of the first cryptographic device and the alternative version of the secret value may comprise a randomly-skewed version of the key or other parameter.

Randomly skewing secret values as a countermeasure to compromise

Methods and apparatus are provided for silent alarm channels using one-time passcode authentication tokens. A message is transmitted indicating a potential attack on a protected resource by obtaining the message; combining the message with a tokencode generated by a security token to generate a one-time passcode; and transmitting the one-time passcode to a receiver. A plurality of the messages can be obtained in parallel, and the plurality of parallel messages can be combined with the tokencode to generate the one-time passcode. A subsequent message can optionally be generated by applying a hash function to a prior n-bit value to provide a counter identifying each message. The message optionally also comprises one or more additional bits to provide an annotation of the message.

Methods and apparatus for silent alarm channels using one-time passcode authentication tokens

A processing device is configured to identify a plurality of defensive security actions to be taken to address a persistent security threat to a system comprising information technology infrastructure, and to determine a schedule for performance of the defensive security actions based at least in part on a selected distribution derived from a game-theoretic model, such as a delayed exponential distribution or other type of modified exponential distribution. The system subject to the persistent security threat is configured to perform the defensive security actions in accordance with the schedule in order to deter the persistent security threat. The distribution may be selected so as to optimize defender benefit in the context of the game-theoretic model, where the game-theoretic model may comprise a stealthy takeover game in which attacker and defender entities can take actions at any time but cannot determine current game state without taking an action.

Scheduling of defensive security actions in information processing systems

An improved technique involves providing protection of secrets by splitting the secret into secret shares and providing tokens for each secret share. Along these lines, a terminal splits a secret such as a credit card number into shares. The terminal then transmits each share to a separate and distinct token server. Each token server, upon receiving a secret share, generates a corresponding token and sends that token to an application server. In some cases, when a user at the application server requires access to the secret, the application server sends each token to the token server form which the token was generated. The token servers each send, in return, a secret share to the application server. The application server combines the secret shares to recover the secret.

Split tokenization

Server methods and apparatus are provided for processing passcodes generated by configurable one-time authentication tokens. An authentication server is configured to process an original passcode generated by a configurable one-time authentication token by configuring the authentication server to have a server configuration that is compatible with a selected configuration of the configurable one-time authentication token; receiving a candidate passcode based on the original passcode generated by the configurable one-time authentication token; and processing the Is candidate passcode based on the server configuration. The selected configuration of the configurable one-time authentication token must always enable a forward-secure pseudorandom number generation feature for the one-time authentication token and at least one additional selected token feature.

Server methods and apparatus for processing passcodes generated by configurable one-time authentication tokens

Configurable one-time authentication tokens are provided with improved resilience to attacks. A one-time authentication token is configured by providing a plurality of token features that may be selectively incorporated into the configurable one-time authentication token, wherein the plurality of token features comprise at least two of the features; obtaining a selection of at least a plurality of the token features: and configuring the one-time authentication token based on the selected token features, wherein the configuration must always enable forward security for the one-time authentication token and at least one additional selected token feature. A configurable one-time authentication token is provided that comprises a plurality of selectable token features that may be selectively incorporated into the configurable one-time authentication token, wherein the configurable one-time authentication token is always configured with the forward security and at least one additional token feature.

Configurable one-time authentication tokens with improved resilience to attacks

A client device or other processing device comprises a file processing module, with the file processing module being operative to provide a file to a file system for encoding, to receive from the file system a proof of correct encoding of the file, and to verify the proof of correct encoding. The file system may comprise one or more servers associated with a cloud storage provider. Advantageously, one or more illustrative embodiments allow a client device to verify that its files are stored by a cloud storage provider in encrypted form or with other appropriate protections.

Remote verification of file protections for cloud data storage

Methods and apparatus are provided for signing data transactions using one-time authentication passcodes. User authentication passcodes are generated by generating a time-based user authentication passcode based on a forward-secure pseudorandom number, wherein the generated time-based user authentication passcode is used for authentication of the user; and generating an event-based user authentication passcode based on a forward-secure pseudorandom number, wherein the generated event-based user authentication passcode is used to sign one or more data transactions. The generation of an event-based user authentication passcode can be performed on-demand. The generation of the event-based user authentication passcode can optionally be performed substantially simultaneously with the generation of the time-based user authentication passcode.

Event-based data signing via time-based one-time authentication passcodes

An improved technique for verifying a license of a software product includes performing license checks with a server and passing to the server, as part of the license checks, a drifting digital code. The drifting code forms a particular drift pattern, which the server detects over the course of multiple license checks. The drift pattern is typically unique, or relatively unique, to the machine on which the software product is run, and changes in a manner that is difficult for malicious users to replicate on other machines. If a second copy of the software is installed, e.g., if the software is pirated, the second copy will produce a drifting code that has its own drift pattern, which differs from that of the initial copy. The server detects the duplicate copy by observing a divergence in the codes it receives during license checks.

Software license management with drifting component

Methods and apparatus are provided for authenticating a user using multi-server one-time passcode verification. A user is authenticated by receiving authentication information from the user; and authenticating the user based on the received authentication information using at least two authentication servers, wherein the received authentication information is based on a secret shared between a security token associated with the user and an authentication authority that provides the at least two authentication servers. For example, the authentication information can comprise a passcode comprised of a tokencode from the security token and a password from the user. The user can be authenticated only if, for example, all of the at least two authentication servers authenticate the received authentication information.

Methods and apparatus for authenticating a user using multi-server one-time passcode verification

Methods and apparatus are provided for generation of forward secure pseudorandom numbers that are resilient to such forward clock attacks. A forward secure pseudorandom number is generated by obtaining a first state scorresponding to a current leaf node &#x3bd;in a hierarchical tree, wherein the current leaf &#x3bd;produces a first pseudorandom number r; updating the first state sto a second state scorresponding to a second leaf node &#x3bd;; and computing a second pseudorandom number rcorresponding to the second leaf node &#x3bd;, wherein the second pseudorandom number ris based on a forward clock reset index that identifies an instance of the hierarchical tree, wherein the instance of the hierarchical tree is incremented when one or more criteria indicating a forward clock attack are detected. The forward clock reset index can be encoded in a forward secure manner in the hierarchical tree.

Forward secure pseudorandom number generation resilient to forward clock attacks

A server is configured to communicate with a group of clients over a network. Each of the clients obtains a corresponding informational message comprising security-related information such as an indication of compromise (IOC), inserts noise in the information message to generate an anonymized message, and communicates the anonymized message to the server. The anonymized messages communicated by the respective clients to the server may be configured so as to prevent the server from identifying any individual client associated with a particular one of the anonymized messages, while also allowing the server to extract from the anonymized messages collectively one or more characteristics of the underlying informational messages. A given client may insert noise in an informational message by, for example, selecting a noise value from a specified range of noise values, and combining the informational message and the selected noise value to generate the anonymized message.

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Somerville, MA, United States of America

Marten Van Dijk