Abstract: Disclosed is a method and system for modifying content stored in a blockchain. The method comprises identifying an old block of the blockchain comprising undesired data in a transaction of the old block. An updated block may be created by correcting the transaction of the old block. A new block hash may be determined for the updated block. Corrected form of the transaction may be submitted, as a new transaction, along with the new block hash and the difference between the new block hash and hash of the old block. Miners may be allowed to mine the corrected form of the transaction, along with other new transactions. The other new transactions may be mined, based on a consensus of users of the blockchain, into a new block connected to a tip of the blockchain, and the old block may be edited to introduce the corrected form of the transaction.

Abstract: Disclosed is a method and system for modifying content stored in a blockchain. The method comprises identifying an old block of the blockchain comprising undesired data in a transaction of the old block. An updated block may be created by correcting the transaction of the old block. A new block hash may be determined for the updated block. Corrected form of the transaction may be submitted, as a new transaction, along with the new block hash and the difference between the new block hash and hash of the old block. Miners may be allowed to mine the corrected form of the transaction, along with other new transactions. The other new transactions may be mined, based on a consensus of users of the blockchain, into a new block connected to a tip of the blockchain, and the old block may be edited to introduce the corrected form of the transaction.

Abstract: Disclosed is a system for authenticating a caller. The system assigns a public key and a private key to each Caller Identifications (CLID), of a plurality of CLIDs pertaining to a plurality of mobile telephony numbers. The system stores a plurality of CLIDs and a plurality of public keys, associated to the plurality of CLIDs, over a blockchain formed by the plurality of telephony service providers. The system sends a Multi Data Message Format (MDMF) message to a telephony service provider of a callee. The system analyzes the MDMF message to determine whether the CLID is present over the blockchain. The system enables the telephony service provider of the callee to retrieve a public key, of the plurality of public keys, corresponding to the CLID from the blockchain, when the CLID is present on the blockchain. The system authenticates the caller upon verifying the signature by using the public key.