Finality gadgets are special mechanisms used in blockchain systems to ensure that once a transaction or block is confirmed, it cannot be changed or reversed. They add an extra layer of certainty to prevent disputes or confusion about which data is correct. These gadgets work alongside existing consensus methods to provide a clear point at…
Chain selection rules are the criteria and procedures used by blockchain networks to decide which chain of blocks is considered the valid and authoritative version of the transaction history. These rules are essential when there are competing chains, such as after a network split or temporary disagreement among nodes. By following the chain selection rules,…
Proof of Elapsed Time, often shortened to PoET, is a consensus mechanism used in blockchain networks to decide who gets to add the next block of transactions. It relies on trusted computing environments to randomly assign wait times to participants. The participant whose wait time finishes first gets to create the next block, which helps…
Oblivious Transfer is a cryptographic method that allows a sender to transfer one of potentially many pieces of information to a receiver, but remains unaware of which piece was chosen. At the same time, the receiver only learns the piece they select and nothing about the others. This technique is important for privacy-preserving protocols where…
Secret sharing schemes are methods used to split a secret, such as a password or encryption key, into several parts or shares. Each share is given to a different person or system. Only when a certain number of these shares are combined can the original secret be reconstructed. This approach helps protect sensitive information by…
A key escrow system is a security arrangement where encryption keys are held in trust by a third party, known as an escrow agent. The purpose is to ensure that, under specific circumstances like legal requests or emergencies, the keys can be accessed if needed. This allows encrypted data to be recovered even if the…
Broadcast encryption is a method that allows a broadcaster to send encrypted information so that only specific, authorised users can decrypt and access it. This technique is often used when a message needs to be sent to a group, but not everyone should be able to read it. The broadcaster manages keys so that only…
Identity-Based Encryption (IBE) is a method of encrypting messages so that a person’s public key can be derived from their unique identity, such as their email address. This removes the need for a traditional public key infrastructure where users must generate and exchange certificates. Instead, a trusted authority uses the identity information to create the…
Attribute-Based Encryption (ABE) is a way of encrypting data where access is controlled by the characteristics, or attributes, of the user rather than their identity. Instead of giving someone a key directly, the system checks whether the person trying to access the information has the right set of attributes, such as their role or department….
Functional encryption is a method of encrypting data so that only specific functions or computations can be performed on the data without revealing the entire underlying information. Instead of simply decrypting all the data, users receive a special key that allows them to learn only the result of a chosen function applied to the encrypted…