Abstract: Methods, systems, and computer programs for using an implicit certificate are disclosed. In some aspects, a message and an implicit certificate are accessed. The implicit certificate is associated with an entity. A modified message is generated by combining the message with a value based on the implicit certificate. A digital signature can be generated based on the modified message and transmitted to a recipient. In some aspects, a digital signature from an entity and a message to be verified based on the digital signature are accessed. An implicit certificate associated with the entity is accessed. A modified message is generated by combining the message with a value based on the implicit certificate. The message is verified based on the digital signature and the modified message.

Abstract: Methods, systems, and computer programs for using an implicit certificate are disclosed. In some aspects, a message and an implicit certificate are accessed. The implicit certificate is associated with an entity. A modified message is generated by combining the message with a value based on the implicit certificate. A digital signature can be generated based on the modified message and transmitted to a recipient. In some aspects, a digital signature from an entity and a message to be verified based on the digital signature are accessed. An implicit certificate associated with the entity is accessed. A modified message is generated by combining the message with a value based on the implicit certificate. The message is verified based on the digital signature and the modified message.

Abstract: In some aspects, a message and an implicit certificate are accessed. The implicit certificate is associated with an entity. A modified message is generated by combining the message with a value based on the implicit certificate. A digital signature can be generated based on the modified message and transmitted to a recipient. In some aspects, a digital signature from an entity and a message to be verified based on the digital signature are accessed. An implicit certificate associated with the entity is accessed. A modified message is generated by combining the message with a value based on the implicit certificate. The message is verified based on the digital signature and the modified message.

Abstract: Methods, systems, and computer programs for using an implicit certificate are disclosed. In some aspects, a message and an implicit certificate are accessed. The implicit certificate is associated with an entity. A modified message is generated by combining the message with a value based on the implicit certificate. A digital signature can be generated based on the modified message and transmitted to a recipient. In some aspects, a digital signature from an entity and a message to be verified based on the digital signature are accessed. An implicit certificate associated with the entity is accessed. A modified message is generated by combining the message with a value based on the implicit certificate. The message is verified based on the digital signature and the modified message.

Abstract: Methods, systems, and computer programs for using an implicit certificate are described. In some aspects, an implicit certificate is accessed. The implicit certificate is associated with an entity and generated by a certificate authority. The implicit certificate includes a public key reconstruction value of the entity. Certificate authority public key information is accessed. The certificate authority public key information is associated with the certificate authority that issued the implicit certificate. A first value is generated based on evaluating a hash function. The hash function is evaluated based on the certificate authority public key information and the public key reconstruction value of the entity. A public key value of the entity can be generated or otherwise used based on the first value.

Abstract: Methods, systems, and computer programs for using an implicit certificate are disclosed. In some aspects, a message and an implicit certificate are accessed. The implicit certificate is associated with an entity. A modified message is generated by combining the message with a value based on the implicit certificate. A digital signature can be generated based on the modified message and transmitted to a recipient. In some aspects, a digital signature from an entity and a message to be verified based on the digital signature are accessed. An implicit certificate associated with the entity is accessed. A modified message is generated by combining the message with a value based on the implicit certificate. The message is verified based on the digital signature and the modified message.

Abstract: A computer-implemented authenticated encryption method for converting a plaintext message into a ciphertext message. The method includes dividing the plaintext message into at least two working blocks, each working block having a mathematical relationship to the plaintext message. For each working block, a working block ciphertext is computed as a function of such working block, a deterministic working block initialization vector, and a deterministic working block encryption key. For each working block, a message authentication tag is computed as a function of a deterministic working block message authentication key and at least one of (a) the working block ciphertext computed for such working block and an indication corresponding to the mathematical relationship of such working block to the plaintext message and (b) such working block.

Abstract: The present disclosure relates to systems and methods for secure communications. In some aspects, a method of signalling an interception time period is described. At least one keying information used by a KMF to regenerate a key is stored. A start_interception message is signaled from an ADMF to a CSCF. A halt_message is signaled from the ADMF to the CSCF.

Abstract: Methods, systems, and computer programs for producing hash values are disclosed. A prefix-free value is obtained based on input data. The prefix-free value can be based on an implicit certificate, a message to be signed, a message to be verified, or other suitable information. A hash value is obtained by applying a hash function to the prefix-free value. The hash value is used in a cryptographic scheme. In some instances, a public key or a private key is generated based on the hash value. In some instances, a digital signature is generated based on the hash value, or a digital signature is verified based on the hash value, as appropriate.

Abstract: A system and method are provided for enabling a client device to connect to a network. The method comprises: obtaining an authorization code via a communication channel different from the network, the authorization code corresponding to the client device; and after detecting initiation of a security negotiation protocol by the client device, using the authorization code in at least one security negotiation operation.

Abstract: The present disclosure relates to systems and methods for secure communications. In some aspects, a method of signalling an interception time period is described. At least one keying information used by a KMF to regenerate a key is stored. A start_interception message is signaled from an ADMF to a CSCF. A halt_message is signaled from the ADMF to the CSCF.

Abstract: Systems and methods for secure communications are provided. In some aspects, a method of signalling an interception time period is described. At least one keying information used by a key management service (KMS) to regenerate a key is stored. A start_interception message is signaled from an administration function (ADMF) to a call session control function (CSCF). A halt_message is signaled from the ADMF to the CSCF.

Abstract: Methods, systems, and computer programs for generating random values for encryption operations are described. In some examples, information from a message to be encrypted can be used to refresh the state of a pseudorandom generator. In some aspects, a state parameter of the pseudorandom generator is modified based on information in the message. Modifying the state parameter changes the state parameter from a prior state to a refreshed state based on the information in the message. A random output value is obtained by the pseudorandom generator in the refreshed state. The message is encrypted based on the random output value.

Abstract: A method of securely communicating a message for a financial transaction from a first correspondent to one or more recipients. The method comprises dividing the message into at least two portions. Each portion is intended for a recipient. Each portion intended for receipt by one of the recipients is encrypted with that recipient's public key. The message is signed and transmitted to one of the recipients to enable the recipient to verify the message and further transmit the message to a further recipient.

Abstract: The present disclosure relates to systems and methods for secure communications. In some aspects, an initiator KMS receives, from an initiator UE, one or more values used in generation of an encryption key, which includes obtaining at least one value associated with a RANDRi. The initiator KMS sends the at least one value associated with the RANDRi to a responder KMS. The responder KMS generates the encryption key using the one or more values.

Abstract: There is provided a method for secure communications. The method comprises obtaining a broadcast message, computing a signature for said broadcast message using a private key, and sending a transmission to a communication device. The private key is associated with a certificate and the transmission comprises the signature.

Abstract: A system and method are provided for enabling a client device to connect to a network. The method comprises: obtaining an authorization code via a communication channel different from the network, the authorization code corresponding to the client device; and after detecting initiation of a security negotiation protocol by the client device, using the authorization code in at least one security negotiation operation.

Abstract: Methods, systems, and computer programs for using hybrid encryption schemes are disclosed. In some implementations, a random value is obtained by a pseudorandom generator. A symmetric key is generated based on the random value. A public component is also generated based on the random value. Additionally, an initialization vector is generated based on the random value. The symmetric key and the initialization vector are used to generate an encrypted message based on an input message. The encrypted message and the public component are transmitted to an entity. At least one of the public component or the symmetric key is generated based additionally on a public key of the entity.

Abstract: A system and method are provided for enabling a client device to connect to a network. The method comprises: obtaining an authorization code via a communication channel different from the network, the authorization code corresponding to the client device; and after detecting initiation of a security negotiation protocol by the client device, using the authorization code in at least one security negotiation operation.

Abstract: A system and method enabling a recipient correspondent of a keyed PV signature to convert it to a signature with properties similar to a traditional signature (i.e., where the message is public and may be verified by anyone), removing the keyed aspect of the signature. The recipient correspondent may transfer the converted signature to a third party and provide the third party with a proof of knowledge such that the third party may be convinced that the originator of the signature signed the message.