Cryptographic Properties Sample Clauses
The CRYPTOGRAPHIC PROPERTIES clause defines the requirements and standards for the use of cryptographic methods within the scope of the agreement. It typically specifies which encryption algorithms, key lengths, or security protocols must be used to protect data, and may require compliance with industry standards such as AES or RSA. This clause ensures that sensitive information is adequately safeguarded against unauthorized access or tampering, thereby reducing the risk of data breaches and maintaining the integrity and confidentiality of communications or stored data.
Cryptographic Properties. In this section we summarize the desired properties for a secure group key agreement protocol. Following the model of [18], we define four such properties:
1: Group Key Secrecy guarantees that it is computationally infeasible for a passive adversary to discover any group key. • Forward Secrecy (Not to be confused with Perfect Forward Secrecy or PFS) guarantees that a passive adversary who knows a contiguous subset of old group keys cannot discover subsequent group keys. • Backward Secrecy guarantees that a passive adversary who knows a contiguous subset of group keys cannot discover preceding group keys. • Key Independence guarantees that a passive adversary who knows any proper subset of group keys cannot discover any other group key not included in the subset. The relationship among the properties is intuitive. Backward and Forward Secrecy properties (often called Forward and Backward Secrecy in the literature) assume that the adversary is a current or a former group member. The other properties additionally include the cases of inadvertently leaked or otherwise compromised group keys. Our definition of group key secrecy allows partial leakage of information. Therefore, it would be more desirable to guarantee that any bit of the group key is unpredictable. For this reason, we prove a decisional version of group key secrecy in Section . In other words, decisional version of group key secrecy guarantees that it is computationally infeasible for a passive adversary to distinguish any group key from random number. Other, more subtle, active attacks aim to introduce a known (to the attacker) or old key. These are prevented by the combined use of: sender information, timestamps, unique protocol message identifiers and sequence numbers which identify the particular protocol run. All protocol messages include the following attributes: • sender information: name of the sender, or, equivalently, signer. • group information: unique name of the group. • membership information: names (and other information) of current group members. • protocol identifier: protocol being used (fixed as “STR”). • message type: unique message identifier for each protocol message.
1. Key epoch is the same across all current group members. If a group member receives a protocol message with a smaller than current epoch, it terminates the protocol (suspected replay). • time stamp: current time. Loose time synchronization among group members is assumed. We assume that a group member rejects ...
Cryptographic Properties. In this section we summarize the desired properties for a secure group key agreement protocol. Following the model of [18], we define four such properties:
Cryptographic Properties. In this section we summarize the desired properties for a secure group key agreement protocol. Following the model of [KPT00], we define six such properties: The relationship among the properties is intuitive. The first two (often typically called Forward and Backward Secrecy in the literature) are different from the others in the sense that the adversary is assumed to be a current or a former group member. The other properties additionally include the cases of inadvertently leaked or otherwise compromised group keys. Forward and Backward Secrecy is a stronger condition than Weak Forward and Backward Secrecy. Either of Backward or Forward Secrecy subsumes Group Key Secrecy and Key Independence subsumes the rest. Finally, the combination of Backward and Forward Secrecy yields Key Independence. In this paper we do not assume key authentication as part of the group key management protocols. All communication channels are public but authentic. The latter means that all messages are digitally signed by the sender using some sufficiently strong public key signature method such as DSA or RSA. All receivers are required to verify signatures on all received messages. Since no other long-term secrets or keys are used, we are not concerned with Perfect Forward Secrecy (PFS) as it is achieved trivially.
Cryptographic Properties. There are four important security properties encountered in group key agreement. (Assume that a group key is changed m times and the sequence of successive group keys is K = fK0; :::; Kmg).
1. Group Key Secrecy – this is the most basic property. It guarantees that it is computationally infeasible for a passive adversary to discover any group key.
2. Forward Secrecy – (not to be confused with Perfect Forward Secrecy or PFS) guarantees that a passive adversary who knows a contiguous subset of old group keys cannot discover subsequent group keys.
Cryptographic Properties. In this section we summarize the desired properties for a secure group key agreement protocol. Following the model of [KPT00], we define six such properties: ■ Weak Backward Secrecy guarantees that previously used group keys must not be discovered by new group members. ■ Weak Forward Secrecy guarantees that new keys must remain out of reach of former group members. ■ Group Key Secrecy guarantees that it is computationally infeasible for a passive adversary to discover any group key. ■ Forward Secrecy (Not to be confused with Perfect Forward Secrecy or PFS) guarantees that a passive adversary who knows a contiguous subset of old group keys cannot discover subsequent group keys.
Cryptographic Properties. In this section we summarize the desired properties for a secure group key agreement protocol. Following the model of [18], we define four such properties:
1: Group Key Secrecy guarantees that it is computationally infeasible for a passive adversary to discover any group key. Forward Secrecy (Not to be confused with Perfect Forward Secrecy or PFS) guarantees that a passive adversary who knows a contiguous subset of old group keys cannot discover subsequent group keys. Backward Secrecy guarantees that a passive adversary who knows a contiguous subset of group keys cannot discover preceding group keys. Key Independence guarantees that a passive adversary who knows any proper subset of group keys cannot discover any other group key not included in the subset.