In order to use a relative time lock, you need to provide the requirements in the scriptPubKey to which the Bitcoin is sent.
Example
scriptPubKey for escrow with 30 day timeout:
IF
2 3 CHECKMULTISIG
ELSE
"30d" CHECKSEQUENCEVERIFY DROP
CHECKSIG
ENDIF
Then, in order to spend it before 30 days, the scriptSig that satisfies the first conditional statement (multisig script) must be provided, i.e.:
scriptSig: 0
Or after 30 days, alice can provide:
scriptSig:
See BIP112
Sequence
Note that in order to set a relative locktime: the tx must have the following properties:
- version must be 2 or greater
- nSequence must not have 32nd bit set
- nSequence must have the 23rd bit set (
0x400000) if it is a lock-time type, unset for block height type - for relative lock-time type the granularity of each bit is 512 seconds
- for relative block height type each bit represents 1 block
For 30 days, I believe it would be as follows:
30 * 24 * 60 * 60 = 2592000 seconds
2592000 / 512 = 5062.5 ~= 5063 or 0x13C7
sequence = 0x13C7 | 0x400000 = 0x4013C7 or 4199367
nSequence = 0xC7134000 (little endian)
The sequence is the last 4 bytes of an input, see https://en.bitcoin.it/wiki/Transaction
