Secure recovery in a serverless distributed file system

The method of 6 wherein the n authenticators are UMAC message authentication codes.

The method of 6 wherein a user establishes a symmetric key relationship with each member of the distributed directory group.

The method of 6 wherein the number of members required to verify the predetermined number of message authentication codes is f+1 and the predetermined number of message authentication codes is 2f+1, wherein f is the number of faults tolerable by the distributed directory group.

A method for transmitting file writes to a fault tolerant directory group outside of an authenticated channel, the method comprising:

• transmitting one or more file writes to the directory group;
• and
• identifying the one or more file writes with at least one authenticator, the at least one authenticator requiring the directory group to reconstruct at least one secret key to authorize the one or more file writes.

A method for allowing file writes to a fault tolerant directory group outside of an authenticated channel, the method comprising:

• receiving a log from a client machine, the log including the file writes and the log authenticated by a message authentication code;
• and
• reconstructing a secret key associated with the message authentication code, the reconstructing requiring a number of members of the fault tolerant directory group to provide a share of the secret key, the number being at least one plus a number of tolerable faults of the fault tolerant directory group.

A method for file writes to a fault tolerant directory group outside of an authenticated channel, the method comprising:

• creating a log in a client machine, the log including the file writes and the log authenticated by a message authentication code secured with a secret key associated with the message authentication code, wherein reconstruction of the secret key requires a number of members of the fault tolerant directory group to provide a share of the secret key, the number being at least one plus a number of tolerable faults of the fault tolerant directory group;
• and
• transmitting the log outside the authenticated channel.

A serverless distributed file system comprising:

• at least 3f+1 participating computer members forming a group, wherein f represents a number of faults tolerable by the group;
• and
• and a plurality of files distributed among the members of the group, wherein the group requires at least one authenticator for file creation and the group requires the authenticator for file uploads to the serverless distributed file system and changes to any one of the plurality of files is according to predetermined criteria indicated by the authenticator associated with the file.

A computer-readable medium having computer-executable instructions for enabling file writes to a fault tolerant directory group outside of an authenticated channel, the computer-executable instructions performing acts comprising:

• creating a log, the log including the file writes and the log authenticated by a message authentication code secured with a secret key associated with the message authentication code, wherein reconstruction of the secret key requires a number of members of the fault tolerant directory group to provide a share of the secret key, the number being at least one plus a number of tolerable faults of the fault tolerant directory group;
• and
• enabling a client machine to transmit the log outside the authenticated channel.

A computer-readable medium having computer-executable instruction for performing acts for transmitting file writes to a fault tolerant directory group outside of an authenticated channel, the acts comprising:

• transmitting one or more file writes to the directory group;
• and
• identifying the one or more file writes with at least one authenticator, the at least one authenticator requiring the directory group to reconstruct at least one secret key to authorize the one or more file writes.

A computer-readable medium having computer-executable instructions for performing acts for allowing file writes to a fault tolerant directory group outside of an authenticated channel, the acts comprising:

• receiving a log from a client machine, the log including the file writes and the log authenticated by a message authentication code;
• and
• reconstructing a secret key associated with the message authentication code by a predetermined number of members of the fault tolerant directory group disclosing a correct share of the secret key, the reconstructing of the secret key verifying the authenticity of the file writes when an authenticated channel is unavailable.