摘要 |
The invention concerns signature scheme methods whereof the security is based on the discrete logarithm problem, a first scheme for total recovery of the message, a second scheme for partial recovery of the message. The invention also concerns two techniques for reducing to a minimum the total size of the message to be transmitted and of the signature. The first technique consists in including part of the message inside the signature by appropriately selecting the random data used when the signature is generated. The second technique consists in eliminating part of the octets representing the signature, the total recovery of the signature being obtained during the second verification phase. Said schemes and said two techniques aim at reducing the overall size of the signature and of the message to be transmitted. They are therefore particularly designed to be used on portable media such as smart cards. |