Methods and systems for generating and validating value-bearing documents include an issuer module that receives requests for value-bearing documents. The issuer module communicates the requests to a guarantor module. The requests may include a desired security level and/or a target validator. The guarantor module generates value-bearing documents for each request and randomly or pseudo-randomly selects an encryption key from a set of encryption keys to encrypt the value-bearing document. The set of encryption keys may be a key space selected based on the target validator and/or requested security level. The guarantor module encrypts the value-bearing document using the selected encryption key and forwards the document to the issuer. The issuer forwards the encrypted value-bearing document to the requester. When the requester desires to redeem the document, the requester presents the value-bearing document to a validator. The validator extracts an index from the value-bearing document, uses the index to determine a decryption key, and validates the document using the key.