Abstract: A canary value is used to validate a message from a non-web browser client application to a web server providing web services to mitigate cross-site forgery attacks. The canary value is generated by the server in party by applying a hash function to a user identifier and a time stamp. The server provides the canary value to the client application in response to receiving a message that does not have a canary or has an expired canary. The client application upon receiving an error message with a canary message will resend the prior message with the canary value present. The client application caches the canary value for subsequent messages until a new canary value is received. The canary value allows the server to ignore messages generated by the client application under control of an attacker.

Abstract: A secure hash, such as a Hash-based Message Authentication Code (“HMAC”), is generated using a piece of secret information (e.g., a secret key) and a piece of public information specific to each escrow key (e.g., a certificate hash or public key). Using the secret key ensures that escrow key validation data can only be generated by knowing the secret key, which prevents an attacker from generating the appropriate escrow key validation data. Using the certificate hash as the public data ties each escrow key validation data to a particular certificate, thereby preventing the attacker from simply copying the validation data from another escrow key. Any escrow key that is found to be invalid may be removed from the file container and a system audit log may be generated so that a company, individual, or other entity can be aware of the possible attempt at a security breach.

Abstract: A canary value is used to validate a message from a non-web browser client application to a web server providing web services to mitigate cross-site forgery attacks. The canary value is generated by the server in party by applying a hash function to a user identifier and a time stamp. The server provides the canary value to the client application in response to receiving a message that does not have a canary or has an expired canary. The client application upon receiving an error message with a canary message will resend the prior message with the canary value present. The client application caches the canary value for subsequent messages until a new canary value is received. The canary value allows the server to ignore messages generated by the client application under control of an attacker.

Abstract: A secure hash, such as a Hash-based Message Authentication Code (“HMAC”), is generated using a piece of secret information (e.g., a secret key) and a piece of public information specific to each escrow key (e.g., a certificate hash or public key). Using the secret key ensures that escrow key validation data can only be generated by knowing the secret key, which prevents an attacker from generating the appropriate escrow key validation data. Using the certificate hash as the public data ties each escrow key validation data to a particular certificate, thereby preventing the attacker from simply copying the validation data from another escrow key. Any escrow key that is found to be invalid may be removed from the file container and a system audit log may be generated so that a company, individual, or other entity can be aware of the possible attempt at a security breach.