Computer-implemented method of executing instructions stored in a computer memory, using a computer processor, to provide communication verification (b) of digital communications between at least two computing devices (106/110; 108) having access to at least one shared communication channel, with verification indicating the ability to obtain message content, the method comprising: observing, at a verifier (102, 306) and on the at least one shared communication channel, a manicoded key provided on the at least one shared communication channel, the manicoded key including a key manifest (132, G, pk, S) for a secret key (sk), the key manifest providing an argument of knowledge (S, 402) for the secret key indicating to the verifier (102, 306) that a message recipient has access to the secret key (sk), wherein the argument of knowledge for the secret key is calculated based on the secret key (sk); observing, at the verifier (102, 306) and on the at least one shared communication channel, a manicoded message provided on the at least one shared communication channel by a message sender, the manicoded message including message content and a message manifest (126, G, pk, T) for the secret key, the message manifest including an implication argument of knowledge (T, 404) indicating to the verifier that the access to the secret key enables access to the message content by virtue of availability of an extraction process that is executable by the message recipient independently of the verifier; and comparing the key manifest and the message manifest at the verifier to verify (b=1) that the message recipient has the access to the message content, by virtue of the availability of the extraction process and the access to the secret key, to thereby provide the communications verification as the ability to obtain message content. observing, at a verifier (102, 306) and on the at least one shared communication channel, a manicoded key provided on the at least one shared communication channel, the manicoded key including a key manifest (132, G, pk, S) for a secret key (sk), the key manifest providing an argument of knowledge (S, 402) for the secret key indicating to the verifier (102, 306) that a message recipient has access to the secret key (sk), wherein the argument of knowledge for the secret key is calculated based on the secret key (sk); observing, at the verifier (102, 306) and on the at least one shared communication channel, a manicoded message provided on the at least one shared communication channel by a message sender, the manicoded message including message content and a message manifest (126, G, pk, T) for the secret key, the message manifest including an implication argument of knowledge (T, 404) indicating to the verifier that the access to the secret key enables access to the message content by virtue of availability of an extraction process that is executable by the message recipient independently of the verifier; and comparing the key manifest and the message manifest at the verifier to verify (b=1) that the message recipient has the access to the message content, by virtue of the availability of the extraction process and the access to the secret key, to thereby provide the communications verification as the ability to obtain message content.